Question

5tens and 13ones is equal?

Answer 1

Think of the : as tens.
Think of the @ as ones.

: : : : : = 50

@ @ @ @ @ @ @ @ @ @ @ @ @ = 13
 
Now solve (equation below):$50+13=63$

Answer 2

63 
5 tens equals 50
13 ones equals 13 
50 +13 = 63