Answers

2015-03-24T03:32:13+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.
P = Rs 12,000
After one year the sum accumulated with compound interest
             = P (1 +r/100) = 12,000+120 r
Rs 4,000 is returned.
Remaining amount = 8,000 + 120 r  at the end of 1st year.

Sum accumulated at the end of 2nd year = (8,000+120r)(1 + r/100)
         = 8,000 + 200 r + 1.2 r²
I am not sure if the compound interest for the second year is to be taken as :
         8,000 + 200 r + 1.2 r² - (8,000 + 120 r) = 1.2 r² + 80 r
 
  hence,  1.2 r² + 80 r = 920    => 3 r² + 200 r - 2300 = 0
                     3 r² +230 r - 30 r - 2300 = 0
                 (3 r + 230) r - 10 (3 r + 230) = 0
                    r = 10 %  as r is positive we ignore the negative root.
  
accumulated sum at the end of 2nd year = 8,000 + 200 * 10 + 1.2 * 10²
     = Rs 10,120

1 5 1