A sum of Rs 2525 is lent out in two parts in such a way that the interest on one part at 7% for 4 years is equals to that on another part at 6% for 7 years. Find the difference between the two parts of the sum.

Rs. 505

Total sum = P =  P₁ + P₂

ATQ,

P₁ x 7% x4   =   P₂ x 6% x 7

P₁ x 28%      =   P₂ x 42%

2 x P₁           =   3 x P₂

⇒ P₁   :    P₂ =   3  :   2    = 5R (Total)

⇒ 5R = 2525,

1R = 505

Difference b/w P₁ and P₂ = 1R = 505