Question

A number is thrift if it is a multiple of 2 or 3. How many thrift numbers are there between -15 and 15

(a) 18 (b) 9 (c) 19 (d) 15

Answer 1

(a) 19.

Explanation:

The even numbers in the given range are -14, -12, -10, -8, - 6 , -4 and -2. and 7 more of their positive values. Total 14.

The numbers divisible by 3 and not 2 are -9, -3, 3 and 9.

Also 0 is a multiple of any number

Thus, number of thrift numbers are 14 + 4 + 1 = 19 (answer).