CBSE Class 8 Mathematics Rational Numbers Assignment Set A

Question. If a = 7, then the value of − (1-2a/a-5) is _________.
(A) −13/2
(B) −15/2
(C) 13/2
(D) 15/2
Answer : C

Question. Which of the following statements is TRUE?
(A) Every point on the number line represents a rational number.
(B) The product of a rational number and its reciprocal is 0.
(C) (17 × 12)^–1 = 17–1 × 12
(D) Reciprocal of 1/a, a ≠ 0 is a.
Answer : D

Question. Divide the sum of 65/12 and 12/7 and by their difference.
(A) 599/311
(B) 680/216
(C) 642/133
(D) 501/301
Answer : A

Question. The rational number which is not lying between 5/16 and 1/2 is _________.
(A) 3/8
(B) 7/16
(C) 1/4
(D) 13/32
Answer : C

Question. The sum of the additive inverse and multiplicative inverse of 1/5 is ________.
(A) 24/5
(B) − 24/5
(C) 25
(D) –25
Answer : A

Question. The mul t i p l i c a t ive inverse of − a/b is _________.
(A) a/b
(B) b/a
(C) − b/a
(D) None of these
Answer : C

Question. Which of the following properties of rational numbers is given below?
7/4 x (-8/3 + -13/12) = 7/4 x -8/3 + 7/4 x -13/12
(A) Commutativity of addition
(B) Associativity of multiplication
(C) Distributivity of multiplication over addition
(D) Distributivity of addition over multiplication
Answer : C

Question. If x = 2 + 3 × 2 − 5, then |–x| is equal to ________.
(A) 8/5
(B) − 8/5
(C) 0
(D) 1
Answer : A

Question. Mrs Priya earns ₹ 18000 per month. She spends 7/12 on household items and 1/8 on rest of the things. The amount she saves is ________.
(A) ₹ 7120
(B) ₹ 5250
(C) ₹ 5520
(D) ₹ 6562.50
Answer : B

Question. The product of two rational numbers is −28/81. If one of the numbers is 14/27, then find the other number.
(A) 2/5
(B) 8/17
(C) − 2/3
(D) − 4/3
Answer : C

Question. Simplify : (3/11 x 5/6) - (9/12 x 4/3) + (5/13 x 6/15)
(A) − 177/286
(B) − 303/40
(C) 289/492
(D) 17/24
Answer : A

Question. What should be subtracted from (3/4 - 2/3) to get −1/6 ?
(A) − 6/13
(B) 1/4
(C) 2/7
(D) − 1/8
Answer : B

Question. Simplify : 3/8 + 7/2 + (-3/5) + 9/8 + (-3/2) + 6/5
(A) −2/3
(B) −41/10
(C) 39/5
(D) 41/10
Answer : D

Question. If x = 2/3 and y = 3/2, then find the value of (x + y) ÷ (x – y).
(A) 15/2
(B) −13/5
(C) 17/6
(D) −11/6
Answer : B

Question. Which of the following options is true ?
(A) 5/7 <7/9 < 9/11 < 11/13
(B) 11/13 < 9/11 7/9 < 5/7
(C) 5/7 < 11/13 < 7/9 < 9/11
(D) 5/7 < 9/11 < 11/13 < 7/9
Answer : A

Question. If x = − 4/11, then which of the following rational number lies between x and |x|?
(A) 7/13
(B) − 11/15
(C) − 2/11
(D) 5/8
Answer : C

Question. One fruit salad recipe requires 1/2 cup of sugar. Another recipe for the same fruit salad requires 2 tablespoons of sugar. If 1 tablespoon is equivalent to 1/16 cup, then how much more sugar does the first recipe require?
(A) (4/5) cup
(B) (6/5) cup
(C) (3/8) cup
(D) (5/8) cup
Answer : C

Question. The wingspans of different species of birds is given below.

How much longer is the wingspan of a Golden eagle than the wingspan of a Blue jay?
(A) (209/100)cm
(B) (209/100)m
(C) (9/100m
(D) (215/100)cm
Answer : B

Question. There are few adults and children in a restaurant. If 3/8 of the people in the restaurant are adults and there are 90 more children than adults, then how many children are there in the restaurant?
(A) 180
(B) 200
(C) 225
(D) 230
Answer : C

Question. Fill in the blanks.
(i) 0 is neither P nor Q .
(ii) R has/have no reciprocal.
(iii) The rational numbers S and T are equal to their reciprocal.
           P                   Q             R        S          T
(A) Positive       negative         1        1/2      –1/2
(B) Integer         rational          0      –1            0
(C) Positive       negative         0        1         –1
(D) Natural        integer         –1        1          –1
Answer : C

Question. Which of the following options holds?
Statement - 1 : Rational numbers are closed under division.
Statement - 2 : The value of
(−7/18 × 15/-7) - (1x 1/4) + (1/2 x 1/4) is 17/24.
(A) Both Statement - 1 and Statement - 2 are true.
(B) Statement - 1 is true and Statement - 2 is false.
(C) Statement - 1 is false but Statement - 2 is true.
(D) Both Statement - 1 and Statement - 2 are false.
Answer : C

Question. State ‘T’ for true and ‘F’ for false.
(i) The rational number −8/-3 lies neither to the right nor to the left of zero on the number line.
(ii) The rational numbers 1/2 and 5/2 are on the opposite sides of 0 on the number line.
(iii) 0 is the smallest rational number.
(iv) For every rational number x, x + 1 = x.
     (i)            (ii)           (iii)          (iv)
(A) F             T              T              F
(B) T             F              F              F
(C) F             T              F              F
(D) T             T              F              F
Answer : C

Question. There are 42 students in a class. Out of these, 3/4 of the boys and 2/3 of the girls come to school by bus. The total number of boys and girls of the same class who come to school by bus is 30.
How many boys are there in the class?
(A) 20
(B) 24
(C) 26
(D) 16
Answer : B

Question. Which of the following options is INCORRECT?
(A) The rational number 0 is the additive identity for rational numbers.
(B) The additive inverse of the rational number a/b is –a/b and vice-versa.
(C) Rational numbers are closed under the operations of subtraction, multiplication and division.
(D) There are infinite rational numbers between any two rational numbers.
Answer : C

Question. Match the following.

(A) (P) → (iv); (Q) → (iii); (R) → (i); (S) → (ii)
(B) (P) → (i); (Q) → (iii); (R) → (iv); (S) → (ii)
(C) (P) → (iv); (Q) → (iii); (R) → (ii); (S) → (i)
(D) (P) → (i); (Q) → (iv); (R) → (iii); (S) → (ii)
Answer : A
 

Very Short Answer type Questons

Question. What is the value of 1/2 + 1/2 + 1/2
Answer : 3/2

Question. Simplify : 1/3 + (-3/4) + 7/8
Answer : 11/24

Question. Simplify : 7/8 x 1(1/7) = .........
Answer : 1

Question. The product of two rational numbers is 15/11 If one rational number is 5/9 then find the other.
Answer : 27/11

Question. Find the missing number ‘y’ -3/2 + 7/5 = y - 3/2
Answer : 7/5

Question. Find the multiplicative inverse of 4(2/3)
Answer : 3/14

Question. What is the multiplicative inverse of -11/3 x -4/5
Answer : -15/44

Question. What is the value of 3/8 x (-5/7) + 3/7 + 3/8 x 4/7
Answer : 21/56 = 3/8

Question. What is the value of 1 - (1/2) x 2
Answer : 0

Question. Simplify (15/17 + 21/34) + 9/34
Answer : 30/17

Question. What number should be added to 5/16 so that we get the rational number 77/48
Answer : 2/3

Question. What is the multiplicative inverse of -2(2/7)
Answer : –7/16

Question. Complete the following ........... + (-4/9) = -4/9
Answer : 0

Question. Find 5/12 + 3/8
Answer : 19/24

Question. What is the reciprocal of 8 x 3/2.
Answer : 1/12

Q1. Fill in the blanks:

a) Rational numbers are numbers of the form_______ where p,q are integers and q 0.

b) Rational numbers are not closed under___________.

c) _______________ is called the additive identity of rational numbers.

d) Zero has __________ reciprocal.

e) The numbers________ and _______ are their own reciprocals.

f) _____________ is the multiplicative inverse of . 3¹/₃

g) The rational number that is equal to its negative is ____________.

h) There are ______________ rational numbers between any two given rational numbers.

i) Nine times the reciprocal of a number is 3. The number is __________.

j) ___________ + ³/₇ = -1.

Please click the link below to download CBSE Class 8 Mathematics Rational Numbers Assignment Set A