Practice Important Work Time Questions

1. If A can finish a work in 3 days, B can finish the work in 6 days, then How many days together takes to finish the work?

Tips and Tricks to solve Time and work problems:

As per short cut method answer is 3*6/(3+6) = 18/9 = 2 days

One more trick to solve this type of Aptitude problems on time and work
Tricks and tips: Let Assume the job is 6 units (L.C.M of 3 and 6) (whatever it may be like making burgers or walking kilometers etc)

                A–> 3 days – > 6/3 = 2 units per day
B–> 6 days – > 6/6 = 1 unit per day
————————————————-
A+B -> 3 units per day        

The total job is 6 units, so  A and B together complete the work in 6/3 = 2 days.

2. If A can finish a work in 12 hours, B can finish the same work in 15 hours, then How many minutes together takes to finish the work?

Tricks to solve Time and work problems Aptitude :

Let Assume the job is 60 units (L.C.M of 12 and 15)

                A– > 12 hours – > 60/12 = 5 units per day
B– >  15 hours – > 60/15 = 4 unit per day
————————————————-
A+B – > 9 units per day

The total job is 60 units, so  A and B together complete the work in 60/9 = 20/3 hours
= 20*60/3 minutes = 400 minutes

3. A can do the work in 20 days, B can do the same work in 30 days. A,B and C together completed work in 10 days. In how many days C alone can do the work?Tricks and Tips to solve Time and work Aptitude problems:

                Total work = 60 units  (LCM of 20, 30,10)
A can do 3 units per day
B can do 2 units per day
A & B & C can do 6 units per day

                A– > 3
B— > 2
c- > ?
———
A + B + C –> 6

So C can do 1 unit per day (6-3-2)

Total job is 60 units , So C alone the complete job in 60/1 = 60 days

4. A and B together can complete a work in 12 hours. B and C together can complete a same work in 15 hours. C and A together can complete a same work in 20 hours. In how many hours A & B & C together complete the work?
   A) 5                        B) 6                        C) 10                      D) 12

Time and work problems tricks:

                Total work = 60 units  (LCM of 12, 15,20)
A & B– > 60/12 = 5 units/day
B & C— > 60/15 = 4 units/day
C & A– > 60/20 = 3 units/day
———————————————————————–
2 (A + B + C) = 12 units/ day
= >(A + B + C) = 6 units/ day

Total job is 60 units. So A & B & C together complete the work in 60/6 = 10 days

5. A and B together can complete a work in 12 hours. B and C together can complete a same work in 15 hours. C and A together can complete a same work in 20 hours. In How many hours B alone complete the task?

Tricks and Tips to solve Aptitude problems on Time and work with examples:

As the previous question answer (A + B + C) = 6 units/ day
B one day work is (A + B + C) one day work – C & A one day work
B = 6 – 3 = 3 units per day
Total job is 60 units. So B alone can complete the 60/3 = 20 days