10 is the missing number.
Answer:
480 students want more field trips.
60 students is 10%.
Step-by-step explanation:
There are 600 students, and 80% want more field trips.
80% of 600 is 0.8*600 = 8*60 = 480 students.
480 students want more field trips.
Alex bought all the string needed for $125.
It costs $18 for the remaining materials to make each puppet.
So if we closely observe then we see that here $125 is the fixed cost because its not going to change with number of puppets.
And the variable cost is $18.
In this case we can model a Total cost function C(x) for for x number of puppets as below

The total cost to make 50 puppets=$1025
4 minutes 34 seconds will takes to empty the tank, if the starts completely full and oil drained at a rate of 2.5
per minute.
Step-by-step explanation:
The given is,
Tank is shaped like a cylinder that is 3 ft long with a diameter of 2.2 ft.
Oil drained at a rate of 2.5
per minute.
Step:1
Time taken to dry the oil tank is,
T =
....................................(1)
Step:2
Volume of the oil is,
.................................................(2)
Where, r - Radius of Cylinder

r = 1.1 ft
From eqn (1),
V =
×
× 3
= 11.40398 
Step:3
From equation (1)
=
= 4.56
= 4.56 minutes
T = 4 minutes 34 seconds
Result:
Time taken to dry the oil tank is 4 minutes 34 seconds, if a cylinder is 3 ft long with a diameter of 2.2 ft and oil is drained at a rate of 2.5ft^3 per minute.