Question

A man has Rs 1900. he lent some of it at 5% p.a and rest at9% p.a. The total amount of interest which he got after4 years was Rs 580.Wwhat was the sum

ans= Rs650,Rs 1250​

Answer 1

The sum is Rs 1,250 and Rs 650

Explanation:

Let the amounts be represented as $x and $y

The sum of both is 1900

Thus;

x + y = 1,900 •••••(i)

Mathematically, the interest on the amount borrowed is;

I = PRT/100

where p is the principal, representing the amount borrowed

R is the rate

T is the time

for the first amount of $x ; we have interest as;

I = (x * 5 * 4)/100 = 20x/100

for the second, we have

I = (y * 9 * 4)/100 = 36y/100

The sum of both is 580

Thus;

20x/100 + 36y/100 = 580

20x + 36y = 58000 •••••(ii)

From equation i;

x = 1,900 - y

Substitute this into equation ii

We have this as;

20(1900-y) + 36y = 58,000

38000 - 20y + 36y = 58,000

16y = 58000 - 38000

16y = 20,000

y = 20,000/16

y = 1250

From equation 1;

x + y = 1900

x = 1900-y

x = 1900-1250

y = 650