Question

8. A certain sum of money amounts to * 10,880 in 3 years and 11,840 in 4 years. Fi
the principal and rate.
9. 1,200 amounts to 1680 in 5 years. What will * 560 amount in 8 years at sa
rate of interest?​

Answer 1

Answer:

8) p+prt/100 = 10880

p(1+ 3r/100) = 10880 .....(1)

So,  p(1+ 4r/100) = 11840 ....(2)

(1)/(2) :-

(1+ 3r/100) = 10880

(1+ 4r/100) 11840

11840+11840*3r/100=10880*(1+ 4r/100)

11840+1184*3r/10

= 10880 + 1088*4r/10

11840 - 10880 = 1088*4r/10-1184*3r/10

9600 = 800r

r = 96/8 = 12

p = 10880/(1+3r/100)

= 10880/(1+36/100)

= 1088000/136

= 8000

Therefore P = 8000 and R = 12%

9) R = 100 x 480 / 5 x 1200 = 8%

Interest for 8 yrs = 560 x 8 x 8 /100 = 358.40

Amount =  Rs.9I8.40