A new photocopier can make 72 copies in 2 min. When an older photocopier is working, the two photocopiers can make 72 copies in 1.5 min. How long will it take the older photocopier working alone to make 70 copies?
How would you set it up? Would it be (72/2) + (72/1.5)= (70/x)? we didn't do examples in class
I wrote out all those copies/ min and such for a reason. In problems like this if you keep track of the units, it is hard to go far off course.
I am stuck on this one too :(
To solve this problem, we can set up a system of equations.
Let's assume that the older photocopier can make x copies in one minute.
From the first piece of information, we know that the new photocopier can make 72 copies in 2 minutes. This means that the new photocopier makes 72/2 = 36 copies per minute.
From the second piece of information, we know that when the older photocopier is working together with the new photocopier, they can make 72 copies in 1.5 minutes. This means that together, they make 72/1.5 = 48 copies per minute.
Now, we can set up the following equation:
x + 36 = 48
By solving this equation, we can find the value of x, which represents the number of copies the older photocopier can make in one minute.
x = 48 - 36
x = 12
Therefore, the older photocopier can make 12 copies per minute.
To find out how long it will take the older photocopier to make 70 copies, we can set up another equation:
12t = 70
Where t represents the time it takes for the older photocopier to make 70 copies.
Solving for t:
t = 70/12
t ≈ 5.83
Therefore, it will take the older photocopier approximately 5.83 minutes (or 5 minutes and 50 seconds) to make 70 copies.
new --> 36 copies/min
old --> n copies/min
new + old = (n+36) copies/min
(n+36)copies/min * 1.5 min = 72 copies
1.5 n + 54 = 72
1.5 n = 18
n = 12 copies/min
12 copies/min * t = 70 copies
t = 35/6 = 5.83 min