Question

divide rupees 17100 into two parts such that the simple interest on the first part for 3 years at 7% per annum is equal to the simple interest on the second part for 4 year at 9% per annum.​

Answer 1

Answer

Let first part of 17100 is x and other part is (17100 - x)

case 1 : P = x , t = 3 years and R = 7% per annum.

so, S.I = P × R × t /100

= x × 7 × 3/100

= 21x/100

hence, S.I = 21x/100 .....(1)

case 2 : P = 17100 - x , R = 9% per annum and t = 4 years

so, Simple interest , S.I = P × R × t/100

S.I = (17100 - x) × 9 × 4/100

S.I = 36(17100 - x)/100 .....(2)

from question,

21x/100 = 36(17100 - x)/100

or, 21x = 36(17100 - x)

or, 7x = 12(17100 - x)

or, 7x = 12 × 17100 - 12x

or, 19x = 12 × 17100

or, x = 12 × 900 = 10,800

hence, first part is 10,800 and 2nd part is (17,100 - 10,800) = 6,300