Question

what is the sum of all the two digit numbers which are divisible by 5?

Answer 1

Start with the first two digit number divisible by 5, (10), and the last (95)
Is this an algebra II level class? You'd probably want to use formulas for arithmetic sequences there
S=(n(a1+an))/2
a1=10, an=95, n= 17 i think

If that all seems very foreign, you probably havent done it yet, then you can easily just add by hand
10+15+20+25+....+95

Answer 2

but the answer in this question is 945.

Answer 3

i want to know how what formulation is use to get this answer.