Question

a sum of rs 400 amounts to rs 480 in 4 years what will it amount to if the rate of interest is increased by 2 percent per annum

Answer 1

Hi

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.

:)

Answer 2

480-400=(400×r×4)/100
r=(80×100)/(400×4)
r=5
New r=5+2=7
amount =400+(400×7×4)/100
amount=400+112=512