An amount of money appreciates to Rs7000 after 4 years and to Rs 10000 after 8 years at a certain compound interest compounded annually. The initial amount of money was a) Rs 4,700 b) Rs4,900 c) Rs4,100 d) Rs4,300 Kindly show me some way of solving this question in the least amount of time, like in olympiad

1

Answers

  • qais
  • Content Quality
2016-01-27T23:36:15+05:30

This Is a Certified Answer

×
Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Let the amount be P
As we know, A = P(1 + R/100)^t
initially, 7000 = P(1+R/100)^4________(1)
The key point to note here is, after 4 years, Rs 7000 will be the principal and the  amount after further 4 years will be Rs 10000
so,
10000 = 7000(1 +R/100)^4
⇒(1 +R/100)^4 = 10/7 
putting this value in equation (1),
7000 = P×10/7
P = Rs 4900
By applying small logic you can make easier your problems.
0
mark brainliest, if it helped you :)