How many positive three-digit integers are divisible by both 4 and 5?
Pick
A) 40  B) 42  C) 45  D) 50  E) 60
A number to be divisible by both 4 and 5 should be divisible by the least common multiple of 4 and 5 so by 20.   Multiples of 20 between 100 and 999, inclusive is   (last-first)/multiple+1=(980-100)/20+1=44+1= 
<gadget id="calculator">44+1</gadget>
<output>45</output>
45   Answer: 45.
<result>C</result>
How many positive three-digit integers are divisible by both 4 and 5?