Question

A shopkeeper has some calculators after destroying 40%calculators he still has 420 calculators how many calculators he had start with

Answer 1

we have 60% now
$\frac{420}{60} = 7$
so
1%=7
and
40%=280
i .e he has total calculators is
40%+60=420+280=700
A shopkeeper start with 700 calculators




hope it helps you.....