Answer:
a. 7.5 minutes
b. 4 and one-half toothpicks
Explanation:
a. an hour = 60 minutes
Allotted time for the exam = 1/2 hour = 1/2 * 60 = 30 minutes
He used 3/4 of this time, so the time left in fraction would be 1-3/4 = 1/4
So the time left in minutes is 1/4 * 30 = 7.5 minutes
b. The total length he has here is 14 3/5 inches
Now he wants to cut toothpicks of 3 1/5
To know the number of toothpicks he can cut, we simply divide the total length by the length of each toothpick
14 3/5 divided by 3 1/5
= 73/5 divided by 16/5
= 73/5 * 5/16 = 73/16 = 4.5625
which is closer to 4 and one-half toothpicks