Embibe Experts Solutions for Exercise 1: West Bengal Board-2020

If the simple interest of a principal for $n$ years at $r\%$ p.a. be $₹\frac{pnr}{25}$, then the principal will be $₹$_____.

The rate of simple interest per annum reduces from $4\%$ to $3\frac{3}{4}\%$ and for this, a person's annual income decreases by $₹60$. Determine the principle of that person.

Find the capital (in $₹$) which gives $₹1$ as interest per month at $5\%$ rate of interest per annum.

In how many years the interest will be the ${\left(\frac{3}{5}\right)}^{\mathrm{th}}$ of principal at the rate of $10\%$ simple interest per annum?

If a principal becomes twice of it in $10$ years, then the rate of simple interest per annum is

The amount of $Rs 2p$ in $t$ years at the rate of simple interest of $\left(\raisebox{1ex}{$r$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\right)\%$ per annum is $Rs. \left[2p+\left(\frac{prt}{100}\right)\right]$.

If the ratio of a principal and the amounts for $5$ years is $5:6$, then find the rate of simple interest per annum.

Find the number of years for which a principal becomes double at the rate of simple interest of $6\frac{1}{4}\%$ per annum.