Question

If x= 2 cos 2 60°+ 1 and y=2 sin 2 60° +1 then find the value of 'x+y'
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Answer 1

For SI the rate is 8%. for CI the rate is 7.4%

1) Let the amount put be P.

2) Given Interest on the amount be 0.24P

3) Time duration is 3 years.

4) Assuming Simple Interest

SI = PRT/100

Substituting the values 0.24P = PR*3/100

Hence the rate of interest is 8% p.a.

5) Assuming Compound Interest

CI = P((1+ \frac{R}{100})^T -1)P((1+

100

R

)

T

−1)

Substituting the values :

0.24P = P((1+ \frac{R}{100})^3 -1((1+

100

R

)

3

−1 )

R = 100( \sqrt[3]{1.24} - 1 )100(

3

1.24

−1)

R = 7.4%p.a.