Question

paul takes 8 hours to complete a job and lisa takes 10 hours to complete the same job. if they both work together, then how long will they take to complete the job:

Answer 1

..Paul takes 8 hours to complete a job or 1/8 of work per hour

and Lisa takes 10 hours to complete the same job. i.e. 1/10 of work per hour

if they both work together, they do 1/8+1/10 = 9/40 of the work per hour

how long will it take them to complete the job:

1 = all the time, they do 9/40 of the work per hour

time taken: 1:(9/40)= (1*40)/9=4.4444hd approximately 4h26min

Explanation: