Question

A sum of ₹400 amounts to ₹480 in 4 years. What will it amount to, if the rate of interest is increased by 2% per annum.

The answer is ₹512, I just need the explanation.
THANK YOU

Answer 1

Answer:

Interest for 4 years on 400 is 80

Interest for 1 year on 400 is 20

Rate of interest =(100) (20)/400=5

Rate of interest increased by 2%

Now the rate of interest is 7

Amount =P+S.I =400(4)7/100+400=112+400=512

Answer 2

Answer:-

1 ) principal ( p ) = Rs 400

Amount ( A ) = Rs480

Time ( t ) = 4 years

Rate of interest = r %

Simple interest ( I ) = A - p

I = 480 - 400

I = Rs80

r = ( 100 × I ) / pt

r = ( 100 × 80 ) / ( 400 × 4 )

r = 5%

2 ) If rate of interest increased 2 %

Per annum ,

New ( r ) = 5 + 2 = 7%

I = ( ptr ) /100

= ( 400 × 4 × 7 )/100

I = 114

Therefore ,

New amount = p + I

= 400 + 114

= Rs 514

I hope this helps you.