The answer would be 20 because you have 5 blocks that are cut into 1/4. It doesn't say anything about any of the pieces disappearing or being used yet so you multiply 4*5 and then you get the answer.
No because 2/5 equals 4/10, which is .4, not .25 :)
Start by making the denominators equal.
1/3 becomes 4/12
1/6 becomes 2/12
and you have 5/12.
Add together to get 10/12.
Once simplified, the answer should be 5/6.
5.3 minutes.
First, let's calculate the volume of the tank. That will be the area of the base multiplied by it's length. And since it's base is a circle, the area is pi*r^2. So:
V = l*pi*r^2
V = 3.5 * pi * (2.2/2)^2
V = 3.5 * pi * (1.1)^2
V = 3.5 * pi * 1.21
V = 4.235 * pi
V = 13.30464489
So the tank has a volume of about 13.3 ft^3. Now simply divide that volume
by the rate of incoming fluid. So
13.3 / 2.5 = 5.32
Rounding to 2 significant figures gives a time of 5.3 minutes.
Let's represent h with the number of hours:
15h ≥ 200
h ≥ 200/15
h ≥ 40/3
h ≥ 13 1/3
He has to work at least 13 1/3 hours.