This Might Not Be correct But...
If your trying to find X it would be 6.25
You would divide 24 by 1.6 to get 15 so you would divide 10 by 1.6 to get 6.25
So I think Its 6.25 Sorry If im wrong.
Answer:

Step-by-step explanation:
Simple interest (I) = $160
Principal amount (P) = $2000
Time period (t) = 8 months
Let R denotes rate of interest.
Relation between simple interest, principal amount, time and rate of interest is given by 

(f o g)(x) = 2(5x + 1) - 6 = 10x - 4
(g o f)(x) = 5(2x - 6) + 1 = 10x - 29
So (f o g)(x) produces the greatest output.
1490/4 =372.5................