Answer:
rs 28500
Explanation:
If she saves rs3420 and spends 88% we need to convert 88% to a decimal first.
88% = 88/100 = .88
Let m equal her monthly income.
m - .88m = 3420
.12m = 3420
.12m/.12 = 3420/.12
m = 3420/.12
m = 28500
He monthly income is rs28500.