Question

find the rate of interest on rupees 800 fetches 130 Rupees as simple interest in 2 years 6 months

Answer 1

Solution v:

Principal ( p ) = Rs 800

Simple interest ( I ) = Rs 130

Time ( t ) = 2½ years = (5/2 ) years

Let the rate of interest = r %

*****************************************

We know that ,

I = ( ptr )/100

Or

r = ( 100 × I )/( pt )

*************************************

Now ,

r = ( 100 × 130 )/[ 800 × (5/2 ) ]

=> r = ( 100 × 130 )/ ( 400 × 5 )

After cancellation , we get

= 13/2

= 6.5 %

Therefore ,

Rate of interest = r = 6.5%

Or

r = 13/2 %

•••••

Answer 2

13/2 is the correct answer