I’d say 12 but i could be wrong
Given :
________ is 1/10 of (186.79 - 29.09). Round that answer to the nearest tenths and compare it to 15.7. Whichever number is bigger- add that to the difference between 34.45 and 12.6.
To Find :
The final answer.
Solution :
First we need to solve 1/10 of (186.79 - 29.09).
So, 
The equivalent of above expression is 15.77 which is greater than 15.7 .
So, we need to add 15.77 to the difference between 34.45 and 12.6 .

Time = Distance / Speed
1. 240/60 = 4 Hours
2. 6/3 = 2 Hours
3. 90/30 = 3 Hours
Therefore the correct answer is 3.