What was Jonny's original investment?

Question

After one year Jonny's two mutual funds returned $10000. The first fund returned 2%and the second, in which he invested $12,000 more returned 14%. What was Jonny's original investment?

Answer 1

We assume Y is the original investment. So based on the question, we can get 

 

2%*Y+(Y+12000)*14%=10000 So, solving this equation

2%*Y+Y*14%+12000*14%=10000

Y*16%+1680=10000

Y*16%=8320

Y=52000

so his original investment is 52000 dollars.