CBSE Class 8 Mathematics IMO Olympiad MCQs with Answers Set B

LOGICAL REASONING

Question. In a certain code, the word COMEATONCE is written as XLNVZGLMXV. In the same code, which of the following would code OK?
A. KL
B. LM
C. KM
D. LP
Answer : D

Question. Count the number of circles in the given figure.

A. 16
B. 15
C. 17
D. 18
Answer : A

Question. There is a certain rule followed in figures P, Q and R. Identify the rule and find the missing numbers a & b respectively.

A. 336, 84
B. 676, 196
C. 484, 86
D. 576, 194
Answer : A

Question. Seven executives P, Q, R, S, T, U and W reach office in a particular sequence. U reaches immediately before P but does not immediately follow S. R is the last one to reach office. T follows immediately after P and is subsequently followed by W. Who ranks fourth in the sequence of reaching office?
A. W
B. U
C. T
D. None of these
Answer : D

Question. Study the following arrangement carefully and answer the question given below.
R B B D A P $ 3 T J Q 5 4 S * 1 L + V 9 N M
5 ÷ K 7 O
If each symbol is first converted into a numeral and then all the numerals are converted into english letters, how many converted english letters will be there in the above arrangement of elements?
A. 15
B. 11
C. 12
D. 13
Answer : B

Question. Which of the following Venn diagrams best represents the relationship amongst, "Fractions, Rational numbers and Whole numbers"?

Answer : A

Question. There is a certain relationship between the figures P and Q & R and S. Identify the relationship and find the missing figure.

Answer : B

Question. Identify the missing figure in the given figure matrix.

Answer : A

Question. The three different positions of a dice are given below:

Which number is on the face opposite to 1?
A. 6
B. 2
C. 3
D. 5
Answer : B

Question. There is a set of three figures X, Y and Z, showing a sequence of folding of a piece of paper.
Figure (Z) shows the manner in which the folded paper has been cut. Choose the figure which would most closely resemble the unfolded form of paper.

Answer : A

Question. At the end of a business conference 15 people are present. All shake hands with each other once. How many handshakes will there be altogether?
A. 120
B. 91
C. 110
D. 105
Answer : D

Question. Select the correct mirror image of given below combination.

Answer : A

Question. It is 3 o'clock in a watch. If the minute hand points towards the North-East, then the hour hand will point towards the .
A. South
B. South-West
C. North-West
D. South-East
Answer : D

Question. If the first five words in the sentence, "Meeta Meets Mysterious Meena Many Times" are rearranged in the alphabetical order, then which will be the middle word?
A. Meeta
B. Meena
C. Meets
D. Mysterious
Answer : A

Question. Shobha is the niece of Ashish. Ashish's mother is Priya. Kamla is Priya's mother. Kamla's husband is Hari. Krishna is the mother-in-law of Hari. How is Shobha related to Hari?
A. Daughter
B. Great granddaughter
C. Grand niece
D. Great grandson's daughter
Answer : B

MATHEMATICAL REASONING

Question. If (3.9268)² = 15.42, then find the value of √154200.
A. 3926.8
B. 392.68
C. 39.268
D. 3.9268
Answer : B

Question. Which of the following do not vary directly?
A. Speed of a vehicle and time taken to cover a fixed distance.
B. Number of days worked and amount of earnings.
C. Number of books and their price.
D. Number of units of current used and the amount of charge for consumption.
Answer : A

Question. Solve for x : x+9/28 + x−4/3 = 5x−32/9 − 2x−3/35
A. 19
B. –19
C. 29
D. –29
Answer : A

Question. The difference of the area of the circumscribed and the inscribed square of a circle is 35 sq. cm.
Find the area of the circle.

A. 55 sq. m
B. 70 sq. m
C. 55 sq. cm
D. 70 sq. cm
Answer : C

Question. The value of

A. 9/8
B. 6/5
C. 4/9
D. 9/4
Answer : D

Question. By what least number 3600 be divided to make it a perfect cube?
A. 9
B. 50
C. 300
D. 450
Answer : D

Question. Sneha cut the following figure out of a rectangular cardboard of length 70 cm and breadth 50 cm. Find the area of the figure.

A. 2722.5 cm²
B. 2122 cm²
C. 2577 cm²
D. 2257 cm²
Answer : A

Question. In the given figure, the angle formed between the hour and minute hand is

A. 80°
B. 40°
C. 60°
D. 30°
Answer : C

Question. The number of chocolates in the three packets P, Q and R are in the ratio of 2 : 3 : 4. The total number of chocolates in the three packets is 270. Packet R sells 20 chocolates to packet P and 10 chocolates to packet Q. After this sale, what is the ratio of chocolates in packets P : Q : R?
A. 8 : 9 : 10
B. 9 : 10 : 8
C. 8 : 10 : 9
D. 10 : 9 : 8
Answer : C

Question. The perimeter of a rhombus is 146 cm and one of its diagonal is 55 cm. Find the other diagonal and the area of the rhombus.
A. 24 cm, 660 cm²
B. 24 cm, 330 cm²
C. 48 cm, 660 cm²
D. 48 cm, 1320 cm²
Answer : D

Question. A rectangular block of wood has dimensions 24 cm by 9 cm by 7 cm. It is cut up into bricks. Each brick is a cube of side 3 cm. Find the largest number of bricks that can be cut from the block.
A. 48
B. 56
C. 49
D. 52
Answer : A

Question. Simplify : (a + b)³ + (a – b)³ + 6a(a² – b²)
A. 8a²
B. 8a²b
C. 8a³b
D. 8a³
Answer : D

Question. If A : Rational numbers are always closed under division and R : Division by zero is not defined, then .
A. Both A and R are true
B. Both A and R are false
C. A is true and R is false
D. A is false and R is true
Answer : D

Question. Two dice are tossed. The probability that the total score is a prime number is .
A. 1/6
B. 5/12
C. 1/2
D. 7/9
Answer : B

Question. Which of the following statements is incorrect?
A. A number is divisible by 3, if the sum of digits divisible by 3.
B. A number is divisible by 9, if the sum of its digits is divisible by 9.
C. A number is divisible by 4, if the number formed by its last two digits is divisible by 4.
D. A number is divisible by 6, if the number is divisible by either 2 or 3.
Answer : D

Question. How many kg of pure salt must be added to 30 kg of 2% solution of salt and water to increase it to a 10% solution?
A. 2(2/3)kg
B. 3(2/3)kg
C. 4(1/2)kg
D. 6(2/5)kg
Answer : A

Question. Which of the following pie charts represent the data shown below?
Number of students opting different subjects

Answer : B

Question. Simplif

Answer : B

Question. The size of a red blood cell is 0.000007 m and the size of a plant cell is 0.00001275 m. Compare these two, which of the following is correct?
A. A red blood cell is approximately 3/4 of the plant cell in size.
B. A red blood cell is approximately 1/4 of the plant cell in size.
C. A red blood cell is approximately half of the plant cell in size.
D. A red blood cell is approximately equal to the plant cell in size.
Answer : C

Question. A card is drawn from a packet of 100 cards numbered 1 to 100. The probability of drawing a number which is a square is
A. 1/10
B. 9/100
C. 1/100
D. 2/100
Answer : A

EVERYDAY MATHEMATICS

Question. A class starts at 10 a.m. and lasts till 1.27 p.m. Four periods are held during this interval. After every period, 5 minutes are given free to the students. The exact duration of each period is
A. 42 minutes
B. 48 minutes
C. 51 minutes
D. 53 minutes
Answer : B

Question. A man plants 15376 apple trees in his garden and arranges them so that there are as many rows as there are apples trees in each row. The number of rows is
A. 124
B. 126
C. 134
D. 144
Answer : A

Question. The price of tea being increased by 20%, a man reduces his consumption by 20%. By how much percent will his expenses for tea be decreased?
A. 2%
B. 4%
C. 6%
D. 8% 
Answer : B

Question. If a company sells a car with a marked price of ₹ 2,72,000 and gives a discount of 4% on ₹ 2,00,000 and 2.5% on the remaining amount of ₹ 72,000, then the actual price charged by the company for the car is
A. ₹ 2,50,000
B. ₹ 2,55,000
C. ₹ 2,60,100
D. ₹ 2,62,20
Answer : D

Question. Ratio of the earnings of A and B is 4 : 7. If the earnings of A increase by 50% and those of B decrease by 25%, the new ratio of their earnings becomes 8 : 7. What are A's earnings?
A. ₹ 21,000
B. ₹ 26,000
C. ₹ 28,000
D. Data inadequate
Answer : D

Question. A train 150 m long is running with a speed of 68 km/hr. In what time will it pass a man who is running at 8 km/hr in the same direction in which the train is going?
A. 6 sec
B. 10 sec
C. 9 sec
D. 12 sec
Answer : C

Question. A can finish a work in 18 days and B can do the same work in half the time taken by A. Then, working together, what part of the same work they can finish in a day?
A. 1/6
B. 1/9
C. 2/5
D. 2/7
Answer : A

Question. Sam invested ₹ 15,000 at 10% per annum for one year. If the interest is compounded half-yearly, then the amount received by Sam at the end of the year will be
A. ₹ 16,500
B. ₹ 16,525.50
C. ₹ 16,537.50
D. ₹ 18,150
Answer : C

Question. Within a rectangular garden 10 m wide and 20 m long, we wish to pave a walk around the borders of uniform width so as to leave an area of 96 m² for flowers. How wide should the walk be?
A. 1 m
B. 2 m
C. 2.1 m
D. 2.5 m
Answer : B

Question. Tickets numbered 1 to 30 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn bears a number which is a multiple of 5?
A. 1/5
B. 3/5
C. 2/5
D. 1/4
Answer : A

ACHIEVERS SECTION

Question. Find the sum of a, b, c, d, e, f, g and h.

A. 720°
B. 360°
C. 540°
D. 180°
Answer : B

Question. Select the incorrect match.
A. Mean proportion      If A : B = x : y, then B : A = y : x
B. Equivalent ratio       Each term in a ratio multiplied/divided by the same number.
C. Ratio                       Used to compare two or more than two quantities.
D. Proportion               It is an equality relation between two ratios.
Answer : A

Question. Find the numerical value of P : Q where

where a, b, c being all different.
A. 1 : 2
B. 2 : 1
C. 1 : 1
D. None of these
Answer : C

Question. If DE is internal bisector of ∠D, then find x & y respectively.

A. 30°, 150°
B. 20°, 120°
C. 25°, 155°
D. 155°, 25°
Answer : D

Question. Study the statements and choose the correct option.
Statement-1 : The square root of certain decimals are obtained by first changing the decimals into fractions with perfect squares as their numerators and denominators.
Statement-2 : (26.1)² lies between 400 and 900.
A. Statement-1 is true and statement-2 is false.
B. Statement-1 is false and statement-2 is true.
C. Both statements 1 and 2 are false.
D. Both statements 1 and 2 are true.
Answer : D