Question

The difference between the simple and the compound interest compounded every six months at the rate of 10% p.a. at the end of two years is `. 124.05. what is the sum?

Answer 1

Hey there,

Answer:
Rs. 8000

Explanation :

Let the sum be P

Compound Interest on P at 10% for 2 years when interest is compounded half-yearly

=P(1+(R/2)100)2T−P=P(1+(10/2)100)2×2−P=P(1+120)4−P=P(2120)4−PSimple Interest on P at 10% for 2 years = PRT100=P×10×2100=P5

Given that difference between compound interest and simple interest = 124.05

=>P(2120)4−P−P5=124.05=>P[(2120)4−1−15]=124.05=>P[194481160000−1−15]=124.05=>P[194481−160000−32000160000]=124.05=> P[2481160000]=124.05=>P=124.05×1600002481=16000020=8000

Hope this helps!

Answer 2

Compound Interest on P at 10% for 2 years when interest is compoundedhalf-yearly=P1+R21002T-P=P1+1204-P=P21204-PSimple Interest on P at 10% for 2 years= PRT100=P×10×2100=P5Given that difference between compound interest andsimple interest = 124.05P*21204-P-P5=124.05=>P21204-1-15=124.05P=8000