Question

A sum of money lent out at simple interest amounts to rs. 720 after 2 years and to rs. 1020 after a further period of 5 years. find the sum and the rate %

Answer 1

S.I for 5 years = 1020 - 720 = 300..... [Amount for 2 years = 720, A for 7 years = 1020, the difference gives S.I for 5 years]
S.I for each year = 300/5 = 60
Amount after 2 years = 720
S.I for 2 years = 120
Hence P = 720 - 120 = 600
S.I = P*R*T/100
60 = 600*R*1/100
R = 10%
Hence, Sum = 600 and rate% = 10
Hope it helps

Answer 2

Answer:

Step-by-step explanation:

SI for 5 yrs=1020-720=300

SI for 1 yr=300/5=60

SI for 2 yrs=120

So principal = 600

Now, 120=600*2*R/100

R=10℅