Answer:
Option E
Explanation:
I gives : C.I for 3 years = Rs. 2522.
II gives : (C.I)−(S.I) for 2 years at same rate is Rs. 40.
[(1+R100)3−1] =2522 ---(i)
[(1+R100)2−1] −P×R×2100 =40 ---(ii)
On dividing (i) by (ii) we get :
(1+R100)3−1(1+R100)2−1−R50 =252240
⇒R31000000+3R100+3R210000R210000 =126120
⇒R100 +300R =120120 ⇒R2 −6005R +30000 =0
⇒R2−6000R −5R+30000 =0
⇒R(R−6000) −5(R−6000) =0
⇒(R−5)(R−6000) =0
⇒R=5
∴ Both I and II are needed to get R.
∴ Correct answer is (E).