<PRE><B>Question 704664</B>
a manufacturing plant is going to use two different stamping machines to complete an order of 975 units.
 One produces 100 units per hour, while the other produces 75 units per hour.
 How long must each machine operate to complete the order if, during the process, the faster machine is shut down for 2.5 hours for repairs?
:
let t = time operated by the slower machine
then
(t-2.5)= time operated by the faster machine
:
75t + 100(t-2.5) = 975
75t + 100t - 250 = 975
175t = 975 + 250
175t = 1225
t = 1225/175 =
t = 7 hrs by the slower machine and
7 - 2.5 = 4.5 hrs by the faster
:
See if that check out
7(75) = 525 units
4.5(100) = 450 units
-----------------------
total units: 975 </PRE>