Chapter 8 linear appliCaTionS 275- A boy can weed the family garden in 90 minutes. His sister can weed it
in 60 minutes. How long will they need to weed the garden if they work
together? - Robert needs 40 minutes to assemble a bookcase. Paul needs 20 min-
utes to assemble the same bookcase. How long will it take them to
assemble the bookcase if they work together? - Together, two pipes can fill a reservoir in^34 of an hour. Pipe I requires
1 hour 10 minutes ()1^16 hours to fill the reservoir by itself. How long
would Pipe II need to fill the reservoir by itself? - Pipe I can drain a reservoir in 6 hours 30 minutes ( 621 hours). Pipe II can
drain the same reservoir in 4 hours 20 minutes ()4 31 hours. How long will
it take to drain the reservoir if both pipes are used?
✔SOLUTIONS
In the following, t will represent the unknown time.- Worker Quantity Rate Time
Sherry 1 1/t t
Denise 1 1/30 30
Together 1 1/20 20
The equation to solve is^13011
t 20+ = .The LCD is 60t.
11
301
20
60 11
3060 1
20
60 1t
t
ttt
t+=
+
=
+
=+=
−−
=60 1
30360 23
22
60tttt
tt
t
Alone, Denise can mow the yard in 60 minutes.- Worker Quantity Rate Time
Ben 1 1/3 3
Brandon 1 1/t t
Together 1 1/2 2