Question

A can do a piece ofworkin 7days of 9hrs each and b can do it in 6days o f 7hrs each.How long they will take to do it working together 8
2/5hrs a day?​

Answer 1

Answer:3 days

Step-by-step explanation:

LET TOTAL WORK=42 units{ lcm of 6 and 7}

Then for 'A',.  IN 9 hrs 6 units work done thus (2/3 units per hour)

And for B , IN 7 hrs 7 unit work is done thus (1unit per hour)

Therefore total work per hour equal to = 1+(2/3) =5/3 unit per hour

In one day (5/3)*{8+2/5} unit work is completed==14 units

Thus [3 days] are needed to complete 42 unit work.{42/14}.