Mathematics

Exercise 3 (a)
Q8
Answer:
The CI formula for with different rates of interests per year for two years is:
 A = P (1+r/100)

Now for two years ,
first year 10% and
second year 15%

A = P(1+10/100)(1+15/100)
A = P (1.1)(1.15)

Now let's assume

P = 100,
A = (100)(1.1)(1.15)
A = 126.5
 CI = A - P
CI = 100 - 126.5
CI = 26.5

As per the above

If sum is ₹ 100 the CI is 26.5 ₹
So what is the sum of CI of 4240 ₹

Cross multiplying

Sum         CI
100           26.5
?               4240

? = (100 * 4240)/26.5

Sum is = 16000 ₹