Let <em>V</em> be the volume of the tank. The inlet pipe fills the tank at a rate of
<em>V</em> / (5 hours) = 0.2<em>V</em> / hour
and the outlet pipe drains it at a rate of
<em>V</em> / (8 hours) = 0.125<em>V</em> / hour
With both valves open, the net rate of water entering the tank is
(0.2<em>V</em> - 0.125<em>V </em>) / hour = 0.075<em>V</em> / hour
If <em>t</em> is the time it takes for the tank to be full, then
(0.075<em>V</em> ) / hour • <em>t</em> = <em>V</em>
Solve for <em>t</em> :
<em>t</em> = <em>V</em> / ((0.075<em>V</em> ) / hour)
<em>t</em> = 1/0.075 hour
<em>t</em> ≈ 13.333 hours
Answer:
1/3
Step-by-step explanation:
= y2-y1/x2-x1
3-2/1+2
1/3
2370 / (2/5) = x / 1...2370 to 2/5 = x to 1
cross multiply
(2/5)(x) = (2370)(1)
2/5x = 2370
x = 2370 * 5/2
x = 11850/2 = 5925 <== their entire goal
So 4.75 times 42= 199.5 so take 240-199.5= 40.5 so he is correct
B should be the answer or D