Question

What is the formula for principal when rate , time and amount is given

Answer 1

$principal = simple \: interest \: \times \: 100 \div \: rate\% \times time$
To find simple interest
let the principal be x
so , simple interest = amount - principal
=amount - x
subtract and find the answer

With that simple interest find the principal with the help of given formula

You will find the value of x
that is nothing but principal

Hope this answer helps you