Question

alan would take 5 hours to build the wall of a house, and gavin would take 7 hours to build it alone. when they work together, they talk a lot, and their combined output decreases by 26 bricks per hour. working together, they build the wall in 4 hours. how many bricks are in the wall?

Answer 1

Answer:

96 bricks

Step-by-step explanation:

Alan does 1/5 of the job in an hour. Gavin does 1/7 of the job in an hour

Together, 12/35 of the job should be done in an hour. In $2 \frac{11}{12}$ hours, the work should be done.

rate at 4 hours=$2 \frac{11}{12}$*(normal speed-26)

To clarify, x=the normal rate

4 hours(normal rate-26)=$2 \frac{11}{12}$(normal rate)

4(x-26)=$2 \frac{11}{12}$x

x=96