Question 248883
This is a common algebraic work problem, and this following method can be used in many different ways, including solving work task problems, and problems involving filling tanks of water, etc.  Lets go!<br>

set {{{A=24}}} and {{{B=40}}} and use the following work formula:<br>

{{{1/A + 1/B = 1/C}}} where C equals the time it will take both A & B working together, so<br>

{{{1/24 + 1/40=1/C}}} substitution of known quantities<br>

{{{40/960 + 24/960=1/C}}} least common denominator LCD<br>

{{{64/960=1/C}}} simplification<br>

{{{64x=960}}} cross multiplication<br>

{{{C=15}}} solve for C and final answer<br>

so if A and B work together, they will complete the task in 15 hours, which should make sense (ie the 2 people working together should get the task done faster than either single person can)!  :)<br>