Problem 12: A sum of Rs 1550 was lent partly at 5% and partly at 8% simple interest. The total interest received after 3 years was Rs 300. The ratio of amounts lent at 5% and 8% is;

a. 5:8                   b. 8:5                       c.31:6                    d. 16:15

basic mathematics mcqs with solution

Solution:

simple arithmetic questions and answers

R1=5%

R2=8%

Total Simple Interest = Rs 300

Time = 3 years

Money lent at 5% : Money lent at 8% =?

We start by supposing that;

So,

So, for first amount;

For second amount part;

So,

But Yearly interest is calculated by dividing total interest by number of years!

From given data we can calculate it as;

This interest  of given data and our calculated total interests should be same;

Solving for 'y'

So, money lent at 5% interest is Rs 800 and money lentat 8% interest is 1550-y = 1550-800= Rs 750

Their ratio is;

800:750

which finally settles to be

16:15