CBSE Class 10 Mathematics Real Numbers Worksheet Set B

Question. If two positive integers a and b are written as a = x³y² and b = xy³, where x and y are prime numbers, then the HCF (a, b) is:
(a) xy
(b) xy²
(c) x³y³
(d) x²y²

Answer: B

Question. Find the greatest number of 5 digits, that will give us remainder of 5, when divided by 8 and 9 respectively.
(a) 99921
(b) 99931
(c) 99941
(d) 99951

Answer: C

Question. The ratio between the LCM and HCF of 5, 15, 20 is:
(a) 9 : 1
(b) 4 : 3
(c) 11 : 1
(d) 12 : 1

Answer: D

Question. Two alarm clocks ring their alarms at regular intervals of 50 seconds and 48 seconds. If they first beep together at 12 noon, at what time will they beep again for the first time?
(a) 12.20 pm
(b) 12.12 pm
(c) 12.11 pm
(d) none of these

Answer: D

Question. The HCF of 2472, 1284 and a third number N is 12. If their LCM is 2³ × 3² × 5 × 103 × 107, then the number N is :
(a) 2² × 3² × 7
(b) 2² × 3³ × 103
(c) 2² × 3² × 5
(d) 2⁴ × 3² × 11

Answer: C

Question. Two natural numbers whose difference is 66 and the least common multiple is 360, are:
(a) 120 and 54
(b) 90 and 24
(c) 180 and 114
(d) 130 and 64

Answer: B

Question. HCF of 5² × 3² and 3⁵ × 5³ is:
(a) 5³ × 3⁵
(b) 5 × 3³
(c) 5³ × 3²
(d) 5² × 3²

Answer: D

Question. The HCF and the LCM of 12, 21, 15 respectively are
(a) 3, 140
(b) 12, 420
(c) 3, 420
(d) 420, 3

Answer: C

Question. In the following questions, a statement of assertion (A) is followed by a statement of Reason (R).
Choose the correct answer out of the following choices.
Assertion (A): For no value of n, where n is a natural number, the number 6n ends with the digit zero.
Reason (R): For a number to end with digit zero, its prime factors should have 2 and 5.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: A

Question. In the following questions, a statement of assertion (A) is followed by a statement of Reason (R).
Choose the correct answer out of the following choices.
Assertion (A): If LCM of two numbers is 2475 and their product is 12375, then their HCF is 5.
Reason (R): HCF (a, b) × LCM (a, b) = a × b.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: A

Please click on below link to download CBSE Class 10 Mathematics Real Numbers Worksheet Set B