Question

A man deposited ₹10000 in an account which gives simple interest. He withdrew the amount and interest after two years. He would have got ₹64 more, had interest been compounded. What was the rate of interest as a percent ?​​

Answer 1

Answer:

It is given that the man deposited Rs 10000 in a bank at the rate of 5% simple interest annually.

∴ Interest in first year =

100

5

×Rs10000=Rs500

∴ Amount in 15

th

year=Rs10000+

14times

500+500+...+500

=Rs.10000+14×Rs500

=Rs10000+Rs7000

=Rs17000

Amount after 20 years =Rs10000+

20times

500+500+...+500

=Rs10000+20×Rs500

=Rs10000+Rs10000=Rs20000

Answer 2

Answer:

It is given that the man deposited Rs 10000 in a bank at the rate of 5% simple interest annually.

∴ Interest in first year = 5/10×Rs10000=Rs500

∴ Amount in 15 thyear=Rs10000+ (14times)500+500+...+500

=Rs.10000+14×Rs500

=Rs10000+Rs7000

=Rs17000

Amount after 20 years =Rs10000+ (20times) 500+500+...+500

=Rs10000+20×Rs500

=Rs10000+Rs10000=Rs20000