CLASS X_CHAPTER 1_REAL NUMBERS_QUIZ 2

If ‘n’ is a natural number, then which of the following numbers end with zero?

• (3 x 2)ⁿ

• (2 x 5)ⁿ

• (6 x 2)ⁿ

• (5 x 3)ⁿ

• 4

• 28

• 38

• 48

If sum of two numbers is 1215 and their HCF is 81, then the possible number of pairs of such numbers are

• 2

• 3

• 4

• 5

The least number that is divisible by all the numbers from 1 to 10 (both inclusive) is

• 10

• 100

• 504

• 2520

At an international airport, planes take off from five different runways at 3, 4, 8, 12 and 15 minutes intervals. At 7:30am, planes took off from all five runways simultaneously. When will five planes take off together again?

• 7:45am

• 8:15am

• 9:00am

• 9:30am

A forester wants to plant 66 apple trees, 88 banana trees and 110 mango trees in equal rows (in terms of number of trees). Also he wants to make distinct rows of trees (i.e., only one type of trees in one row). The number of minimum rows required is

• 2

• 3

• 10

• 12

The largest number which divides 60 and 75, leaving remainders 8 and 10 respectively,

• 260

• 75

• 65

• 13

The LCM of two numbers is 14 times their HCF. The sum of LCM and HCF is 600. If one number is 280, then the other number is

• 20

• 28

• 60

• 80

Statement of Assertion (A): If product of two numbers is 5780 and their HCF is 17, then their LCM is 340.

Statement of Reason (R): HCF is always a factor of LCM.

• Both A and R are true and R is the correct explanation of A

• Both A and R are true but R is not the correct explanation of A

• A is true but R is false.

• A is false but R is true.

Statement of Assertion (A): The number 5ⁿ cannot end with the digit 0, where n is a natural number.

Statement of Reason (R): Prime factorization of 5 has only two factors, 1 and 5.

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.