Question

14. एक व्यक्ति ने 2500 रु० किसी साधारण ब्याज का रस
तथा 1500 रु० 1% अधिक ब्याज की दर से उधार लिया । 3
वर्ष बाद उसने कुल 525 रु० ब्याज के रूप में चुकाए । ब्याज
की पहली दर निकालें।​

Answer 1

Given :-

• A person Take a loan of Rs.2500 at some Rate.
• And, take Rs.1500 at Rate 1% more Than previous one.
• After Three years He paid total interest of Rs.525.

To Find :-

• First Rate of Interest.

Solution :-

Let us Assume That, First Rate of interest is R% .

we know That,

→ Simple Interest = (Principal * Rate * Time)/100 .

in Case 1 we have :-

→ Principal = Rs.2500

→ Rate = R%

→ time = 3 years.

So,

→ SI = (2500*R*3)/100 = 75R. ----------- Equation (1).

_________________

Now, in second Case we have :-

→ Principal = Rs.1500

→ Rate = (R+1)%

→ time = 3 years.

So,

→ SI = [1500 * (R+1) * 3 ] /100

→ SI = 45(R+1) = 45R + 45 ---------------- Equation (2).

_________________

Now Total interest is given Rs.525.

So, Adding Equation (1) & (2) we get,

→ 75R + 45R + 45 = 525

→ 120R = 525 - 45

→ 120R = 480

→ R = 4% . (Ans).

Hence, First Rate was 4% .