Question

How many positive whole numbers less than 100 are divisible by 3, but not by 2?

Answer 1

Answer:

Step-by-step explanation:

The easiest way to do this is either to find a pattern or list them. We'll list them first.

3 9 15 21 27 33 39 45 51 57 63 69 75 81 87 93  99

17 but there is a pattern

Starting with 3, add 6 to every number you find in the series. There is a formula that covers this

l = a + (n- 1)*d

a = 3

l = 99

d = 6

99 = 3 + (n - 1)*6             Subtract 3

99 - 3 = (n - 1)*6

96 = (n - 1)*6                  Divide by 6

96/6 = (n -1)*6/6

16 = n - 1                        Add 1 to both sides.

16+1 = n - 1 + 1               Combine

17 = n