Question

if 15 envelopes cost rupees 11.25 what is the cost of 20 such envelopes

Answer 1

15 envelopes cost rupees 11.25

so 20 such costs=20*11.25/15

your ans is 15

Answer 2

in this such type of problem

we solve

11.25
-------- × 20
15

= 15 ₹