200 / 7 = 28.57
The last multiple of 7 less than 200 is 7 * 28 = 196
300 / 7 = 42.85
The last multiple of 7 less than 300 is 42 * 7 = 294
The number of multiples of 7 between 200 and 300 is (42 - 28) = 14
They include 7 times every integer from 29 to 42