UPSC CDS 1 2021 Math Paper

Given:
The cost price of 100 mangoes is equal to the selling price of 80 mangoes
Calculation
Let selling price =cost price
According to question,
100×CP=80×SP
CP÷SP=80∕100
CP÷SP=4∕5
Profit percentage =(5−4)÷4×100
Profit percentage =1÷4×100
Profit percentage =25%
Hence, profit percentage =25%