Question

A certain sum amounts to rs 3825 in 4 years and to rs 4050 in 6 years find the rate percent and the sum

Answer 1

Solution:-
Simple interest for 2 years = Rs. 4050 - Rs. 3825 = Rs. 225
And simple interest for 4 years = Rs. 225*2 = 450 Rs.
So, Principal = Rs. 3825 - Rs.450 = Rs. 3375
Now,
Simple interest = (P*R*T)/100
450 = (3375*R*4)/100
13500R = 45000
R = 45000/13500
Rate of interest = 10/3 %
Therefore, Rate of interest is 10/3 % and Principal is Rs. 3375
Answer.

Answer 2

Eq 1-Amount in 4 years =P+I of 4 year =3825

Eq2-Amount in 6 year =P+I of 6 year =4050

Eq2-Eq1=interest of 2 year =4050-3825=225

Intrest of4 year =225×2 =450

P=3825-450 =3375

R= 450×100

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3375×4

= 10

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3