Answer:
5/8 tank
Step-by-step explanation:
if he uses 3/8 of the tank
he has (1- 3/8)
8/8 - 3/8 = 5/8 of the tank left
I believe its D. Not 100 percent sure though
Answer: d. 10
Step-by-step explanation:
We know that the number of combinations of r objects selected from a group of n objects at a time is given by :-

Given : The total number of letters = 5
The number of letters need to select = 2
Then , the number of combinations of 2 letters selected from a group of 5 letters at a time is given by :-

Hence, there are 10 possible selections.

Answer: (x2 - 1) - 5(x - 1)