If at same rate of interest, in 2 years, the simple interest is ₹40 and compound interest is ₹80, then what is the principal (in ₹)?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 10 .
SI = P × R × T / 100
40 = P × R × 2 / 100
PR = 2000
For 2 years:
CI − SI = P × R2 / 10000
80 − 40 = P × R2/ 10000
40 = P × R2 / 10000
PR2 = 400000
PR2 / PR = 400000 / 2000
R = 200
P × 200 = 2000
P = 10