A borrows ₹20,000 from B and C. B lends him a certain sum of money at 25% simple interest per annum, while C lends him the remaining sum of money at 21% simple interest per annum. The total interest paid by A in one year is ₹4,500. The sum (in ₹) borrowed from B is:
- A9,000
- B6,000
- C7,500
- D12,500
Solution & Step-by-step Explanation
Let the sum borrowed from B be ₹x.
Then, the sum borrowed from C is ₹(20000−x).
The simple interest from B for 1 year is:
I
B
=
100
x×25×1
=0.25x
The simple interest from C for 1 year is:
I
C
=
100
(20000−x)×21×1
=0.21(20000−x)=4200−0.21x
The total interest is ₹4,500:
0.25x+4200−0.21x=4500
0.04x=4500−4200
0.04x=300
x=
0.04
300
=
4
30000
=7500
The sum borrowed from B is ₹7,500.
Then, the sum borrowed from C is ₹(20000−x).
The simple interest from B for 1 year is:
I
B
=
100
x×25×1
=0.25x
The simple interest from C for 1 year is:
I
C
=
100
(20000−x)×21×1
=0.21(20000−x)=4200−0.21x
The total interest is ₹4,500:
0.25x+4200−0.21x=4500
0.04x=4500−4200
0.04x=300
x=
0.04
300
=
4
30000
=7500
The sum borrowed from B is ₹7,500.