If the sum of the first n positive integers is S, what is the sum of the first n positive integers divisible by 5, in terms of S ?
Pick one:
A) S/2
B) S
C) 2S
D) 2S + 2
E) 5S
Answer is 5S   Given sum of 1 2 3.....n = S   sum of 5 , 10 , 15 ....5n = 5[sum(1 2 3....n) ] = 5S
<result>E</result>
If the sum of the first n positive integers is S, what is the sum of the first n positive integers divisible by 5, in terms of S ?