Question

A bank offers 5% compound interest calculated on a half-yearly basis. A customer deposits ₹1600 each on 1st January and 1st July of a year. At the end of the year, the amount he would have gained by way of interest is

विकल्प

• ₹120

• ₹121

• ₹122

• ₹123

Answer 1

₹121
Explanation :

Amount = ₹`[1600xx(1+5/(2xx100))^2+1600 xx(1+5/(2xx100))]`

= ₹`[1600xx41/40xx41/40+1600xx41/40]`

= ₹`[1600xx41/40(41/40+1)]`

= ₹`[(1600xx41xx81)/(40xx40)]=₹3321`

∴   CI = ₹(3321 - 3200) = ₹121