Answer:
I don’t know
Step-by-step explanation:
Answer:
its 400 cuz 0.1 is tenth
Step-by-step explanation:
Answer:
91.61
Step-by-step explanation:
thats what i got
Answer:
the amount of time until 23 pounds of salt remain in the tank is 0.088 minutes.
Step-by-step explanation:
The variation of the concentration of salt can be expressed as:

being
C1: the concentration of salt in the inflow
Qi: the flow entering the tank
C2: the concentration leaving the tank (the same concentration that is in every part of the tank at that moment)
Qo: the flow going out of the tank.
With no salt in the inflow (C1=0), the equation can be reduced to

Rearranging the equation, it becomes

Integrating both sides

It is known that the concentration at t=0 is 30 pounds in 60 gallons, so C(0) is 0.5 pounds/gallon.

The final equation for the concentration of salt at any given time is

To answer how long it will be until there are 23 pounds of salt in the tank, we can use the last equation:

You could find the need of pine board by finding the perimeter of the frame. But first you need to equalize the units, because one of them is in feet and the other one is in inches.
18 inches = 18/12 feet
18 inches = 1.5 feet
perimeter = l + w + l + w
perimeter = 2 + 1.5 + 2 + 1.5
perimeter = 7
The perimeter is equal to 7 feet, therefore Carl needs 7 feet of pine board