Answer: $2440
Work Shown
1/4 + 1/5 = 5/20 + 4/20 = 9/20
Ryan spent 9/20 of his monthly salary on rent and utilities combined.
This means he keeps the remaining 11/20 of his monthly salary.
Think of Ryan and his friends eating 9 pieces of cake, out of 20 pieces total. That must mean there are 20-9 = 11 pieces left over.
So,
x = monthly salary
(11/20)x = 1342 dollars remain
11x = 20*1342
11x = 26840
x = 26840/11
x = 2440