Answer:
Step-by-step explanation:
Find attached the solution
The rules of significant figures are: 1. all non zeros are significant. 2. trailing zeros are significant. 3. zeros between non-zeros are signifincant. Hence, applying these to the given.
A. 4 sig figs
B. 1 sig fig
C.6 sig figs
D.1 sig fig
The question says the machine uses up m gallons of oil each hour on weekends.
This means that if the machine works for 24 hours each day, it implies that:

There are only two days on weekends i.e. Saturday and Sunday.
This means that if the amount of oil used in 1 day in the weekend is 24m, then we can say:
Saturday: oil used is 24m
Sunday: oil used is 24m
Total oil used during the weekend is:
Mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm