Question

1)In what time will a sum of Rs 4000 gives an interest of Rs 1200 at 12% interest per annum?

Answer 1

?????????????? "annum" ????????????

me assume this be KOMPOUND INTEREST

and start$=4000, kompound per YEER, 12% interest

yu want end$=start$+1200=4000+1200=5200$

kompound interest: end$=start$*(1.12)^n...n=num yeers

end/start=5200/4000=1.3...=1.12^n

log(1.3)=n*log(1.12)

n=log(1.3)/log(1.12)

n=0.11394335230683737 / 0.11332868530700327

n=1.005425264 yeers

Answer 2

I'm going to assume this is simple interest.

Let time be x.

Interest = Principle*Rate*Time/100 (PRT/100)

1200 = 4000*12*x/100

x = 1200*100/400*12 = 1200*1/40*12 (Cancellation of zeroes) = 1200/480 = 2.5

Time = 2.5 years