Ashish has Rs. 1218 with him. He invested money for Arun and Mahesh at 10% compound interest annually. Arun invested for 11 years and Mahesh for 12 years. Both got equal amounts.  How much (in ₹) did Ashish give to Mahesh?

Correct option is B

Given:
Total money = 1218
Rate = 10%
Time for Arun = 11 years
Time for Mahesh = 12 years
Formula Used:
​$$\text{Amount} = P\left(1 + \frac{R}{100}\right)^T$$​​
Solution:
Let Arun get x, Mahesh get (1218 − x)
​$$x(1.1)^{11} = (1218 − x)(1.1)^{12}$$​​
x = (1218 − x)(1.1)
x = 1339.8 − 1.1x
2.1x = 1339.8
x = 638
Money given to Mahesh = 1218 − 638 = 580