I think you divide 1/2 by -2/5 and then add that to -1/4....
Multiply them back into each other... You would multiply your answer with the number you divided by (the number ouside the table if you used the table... ) and you should get the larger number you divided.
Answer:
The answer is 12.566371, but you're supposed to round it up to 12.56
1. 12.5
2. 4.8
First one I'm not sure but second one I'm pretty sure
Just take each number in the first table and divide it by the total then x by 100
Eg the first one 24/120 x 100 = 20%