280 algebra De mystif ieD
of the job remains.Worker Quantity Rate Time
Pipe I 1 1/6 6
Pipe II 1 1/4 4
Together 3/8 38 3
8/
tt= tThe equation to solve is^1
6+ ^1
4= ^3
8
t. The LCD is 24t.
1
61
43
8
24 1
61
424 3
8
24 1
6+=
+
=
t
tt
t
t ++
=+=
=
=24 1
49469
10 9
9
10ttt
t
tBoth pipes together will be used for 109 hours or 109 ⋅60 = 54 minutes. Hence,
Pipe I will be used for 54 minutes.
Press A can print 100 fliers per minute. Press B can print 150 fliers per min-
ute. The presses will be used to print 150,000 fliers.(a) How long will it take for both presses to complete the run if they work
together?
(b) If Press A works alone for 24 minutes then Press B joins in, how long will
it take both presses to complete the job?These problems are different from the previous work problems because
the rates are given, not the times. Before, we used Q = rt implies r = Q/t.
Here, we will use Q = rt to fill in the Quantity boxes.(a) Press A’s rate is 100, and Press B’s rate is 150. The together quantity is
150,000. Let t represent the number of minutes both presses work
together; this is also how much time each individual press will run.
Press A’s quantity is 100t, and Press B’s quantity is 150t. The together
rate is r = Q/t = 150,000/t.