Solve the problem.
-A contractor finds that it takes Sam Tockett 9 hours to construct a wall of a certain size. It takes Jim Lowell 6 hours to construct the same wall. How long would it take if they worked together?
A) $\frac { 5 } { 18 }$ of an hour
B) $3 \frac { 3 } { 5 }$ hours
C) 1 hour
D) 15 hours

Question

Solve the problem.
-A contractor finds that it takes Sam Tockett 9 hours to construct a wall of a certain size. It takes Jim Lowell 6 hours to construct the same wall. How long would it take if they worked together? 
A) $\frac { 5 } { 18 }$ of an hour
B) $3 \frac { 3 } { 5 }$ hours
C) 1 hour
D) 15 hours

Quizplus · Accepted Answer

Sam constructs 1/9 of the wall per hour, and Jim constructs 1/6 of the wall per hour. Together, they construct $(1/9 + 1/6)$ of the wall per hour, which simplifies to $(2/18 + 3/18) = 5/18$ of the wall per hour. To find the time it takes to build the whole wall, take the reciprocal of 5/18, which gives $18/5$ hours, or $3 \frac { 3 } { 5 }$ hours.

Solve the Problem 518\frac { 5 } { 18 }185​ Of an Hour B)

Solve the Problem $\frac { 5 } { 18 }$ Of an Hour
B)