Chapter 8 linear appliCaTionS 277
The equation to solve is 401 + 201 = ^1 t. The LCD is 40t.
1
40
1
20
1
40 1
40
1
20
40 1
40 1
40
+=
+
=
t
tt
t
t
+
=
+=
=
==
40 1
20
40
240
340
40
3
(^1313)
t
tt
t
t
Together Robert and Paul can assemble the bookcase in 1331 minutes or
13 minutes 20 seconds.
- Worker Quantity Rate Time
Pipe I 1 67
1
76 =^67
7/6
Pipe II 1 1/t t
Together 1 43
1
34 43
/
/ =
3/4
The equation to solve is^6
7
+ ^1 = ^4
3
t
. The LCD is 21t.
6
7
14
3
21 6
7
1 21 4
3
21 6
7
2
+=
+
=
+
t
t
t
t
t 11 1 28
18 21 28
18 18
21 10
21
10
t
t
t
tt
tt
t
t
=
+=
−−
=
=
Alone, Pipe II can fill the reservoir in^2101 hours or 2 hours 6 minutes.^
( 101 of an hour is 101 of 60 minutes and 101 ⋅ 60 = 6 .)