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?
4 answers
How would you set it up? Would it be (72/2) + (72/1.5)= (70/x)? we didn't do examples in class
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
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
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 :(
5 answers