Question

An account earns 10% annual compound interest. The amount in the account after t years is equal to the principal times the expression (1 + 0.10)t, or 1.10t. To the nearest tenth of a percent, what is the monthly compound interest rate?

Answer 1

Assuming that means 1.10^t:

0.10 is for years. To get months divide by 12.
0.10/12 = 0.0083333... 
And (1+0.083333...) = 1.0833333. (You will have to multiply t by 12 also to get it in terms of months)
(1.0833333)^12t