if w is the set of all the integers between 19 and 99 , inclusive , that are either multiples of 3 or multiples of 2 or multiples of both , then w contains how many numbers ?
"multiples of 2 from 19 to 99 = multiples of 2 from 1 to 99 - multiples of 2 from 1 to 18 = [ 99 / 2 ] - [ 18 / 2 ] = 49 - 9 = 40 multiples of 3 from 19 to 99 = multiples of 3 from 1 to 99 - multiples of 3 from 1 to 18 = [ 99 / 3 ] - [ 18 / 3 ] = 33 - 6 = 27 multiples of 2 and 3 bothi . e . 6 from 19 to 99 = multiples of 6 from 1 to 99 - multiples of 6 from 1 to 18 = [ 99 / 6 ] - [ 18 / 6 ] = 16 - 3 = 13 these 8 numbers have been counted twice in both the above calculation while calculating multiples of 2 and 3 i . e . total numbers in w = 40 + 27 - 13 = 54 answer option e"
subtract(add(floor(divide(subtract(99, 19), 3)), divide(subtract(99, 19), 2)), floor(divide(subtract(99, 19), multiply(2, 3))))