Answer:
The correct option is B) 12.
Step-by-step explanation:
Consider the provided information.
Working alone at its constant rate, pump X pumped out ¼ of the water in a tank in 2 hours.
As we know:
,
The rate of pump X is 
of the water is pumped out of the tank, that means only
is left to be pumped out.
All 3 pumps pumped out the remaining
of the water out in 3 hours.
The combined rate of all three pumps is:
Pump Y, working alone at its constant rate, would have taken 18 hours to pump out the rest of the water.
The rate of pump Y =
Let z is the time taken by pump Z, then the rate of pump Z is
.
Therefore,

Multiplying both sides by 24 z.

Hence, the correct option is B) 12.
First you distribute the -12 to the (x+5) getting 144=-12x-60.
Next you add 60 to each side getting 204=-12x
Then you divide each side by -12 getting -17=x, which is the answer.<span />
9514 1404 393
Answer:
y = 0.2·0.5^x
Step-by-step explanation:
An exponential function is generally of the form ...
y = a·b^x
where 'a' is the function value when x=0, and b is the ratio between values for x=1 and x=0.
In the given table, y = 0.2 for x = 0, so a = 0.2.
We find that the value for x = 1 is 0.1, so the value of b is ...
b = 0.1/0.2 = 0.5
Then the exponential function is ...
y = 0.2·0.5^x
Answer:
40 minutes
Step-by-step explanation:
We can solve this problem through finding the proportion...
Let the time taken to travel 8 inches at the speed be x
Hence, 12:60 :: 8:x
We must multiply the extremes and the nears..
Hence,
12x=60×8
x=60×8/12
x=40 minutes