Question

Bhagwanti inherited Rs.12000.00. She invested part of it as 10% and the rest at 12% Her annual form these investements is Rs. 1280.00. How much did she invest at each rate?

Answer 1

♧♧HERE IS YOUR ANSWER♧♧

Let, Bhagwanti invested Rs x at 10% and Rs (12000 - x) at 12%.

Time of investment = 1 year.

The interest in 1 year of Rs x investment at 10% is

A = Rs (x × 1 × 10)/100

= Rs x/10

and the interest in 1 year of Rs (12000 - x) investment at 12% is

B = Rs {(12000 - x) × 1 × 12}/100

= Rs {3 × (1200 - x)}/25

By the given condition :

A + B = 1280

=> x/10 + {3 × (12000 - x)}/25 = 1280

=> x/10 + (36000 - 3x)/25 = 1280

=> (5x + 72000 - 6x)/50 = 1280, since lcm of 10 and 25 is 50.

=> - x + 72000 = 1280 × 50

=> x = 72000 - 64000

=> x = 8000

Therefore, at 10% per annum Rs 8000 and at 12% per annum Rs (12000 - 8000) = Rs 4000 were invested.

♧♧REMEMBER♧♧

If P be the sum, t be time of investment and r be rate of interest, then the interest be :

I = (P × t × r)/100

♧♧HOPE THIS HELPS YOU♧♧