Question

a sum of money gets doubled in 5 years at x simple interest,if the interest was y the sum of money would have become ten fold in 30 years. what is Y-X (in %)?

Answer 1

Answer:

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Step-by-step explanation:

P - principal amount, N= No.of.years, R - rate of interest..

doubles in 5 years.

S.I = PNR/100

P= PR(5) /100

R = 100 / 5 = 20%

Rate of interest = 20%

4 times means

3 P= PNR /100

3 = RN /100

3= 20N /100

N=3*5 = 15 years.

It will become 4 times in 15 years.

Answer 2

Answer:

x-y = 10%

Step-by-step explanation:

lets assume principal=100

p=100

A=200

so, S.I=100

that is double times the principal

S.I=P*N*I

100=100*5*x\100

x\100=1\5

   =20%

the amount becomes 10 times in 30years

so, p=100

a=1000

n=30

i=y\100

s.i=900(1000-100)

that is 9times p

900=100*30*y\100

y=900\30

   =30%

so, now x%-y%=20-30

                        =10%