Question

Rupees 4000 amount to Rs.5000 in 8 years; in what time will Rs.2100 amount to Rs.2800 at the same rate?

Answer 1

In first case :

A = Rs.5000

P = Rs.4000

I = A − P

= Rs.5000 − Rs.4000

= Rs.1000

T = 8 years

∵ SI = `("P" xx "R" xx "T")/100`

∴ R =`(100xx"I")/("P"xx"T")`

R `=(100xx1000)/(4000xx8)`

R `=25/8%`

In the second Case :

A = Rs.2800

P = Rs.2100

I = Rs.2800 − Rs.2100 = Rs.700

R = `25/8%`

∴ T =`(100xx"I")/("P"xx"R")`

`=(100xx700)/(2100xx25/8)`

`=(100xx700xx8)/(2100xx25)`

`=32/3`years

`=10 2/3` years

`=10 2/3xx12` months = `10 24/3` months

= 10 years 8 months