Answer:
4 hours to pay the same amount
and aif you want a 3 hours work you should get carpenter A
Step-by-step explanation:

carpenter A for 3 hours:

carpenter B for 3 hours:

Answer: 1/8 is left over.
Step-by-step explanation:
Tess already at half of the pizza, and Shawn ate a quarter of the pizza.
1/2 + 1/4= 3/4
There is a quarter of pizza remaining, but Molly ate half of that quarter (1/8). There is only 1/8 of pizza left.