Interview Q&A / Aptitude

1. How do you solve time and work problems quickly?

   Convert each person's time into work per day (1 divided by days), add rates when people work together, and divide total work by the combined rate. The LCM method makes it faster. Take total work as the LCM of the days, so each rate becomes a whole number.

   BeginnerIn-depth3 min read
2. 12 men can finish a job in 18 days working 8 hours a day. How many days will 16 men take working 9 hours a day?

   12 days. Total work in man-hours = 12 x 18 x 8 = 1,728. With 16 men at 9 hours a day, daily output = 144 man-hours, so days = 1,728 / 144 = 12.

   BeginnerQuick answer1 min read
3. A and B together finish a job in 12 days. B alone takes 30 days. How long does A take alone?

   20 days. A's daily work = together minus B = 1/12 - 1/30 = (5 - 2)/60 = 3/60 = 1/20. With total work 60 units: together 5 units a day, B 2, so A does 3 units a day and needs 60/3 = 20 days.

   BeginnerQuick answer1 min read
4. A, B and C can finish a job in 10, 12 and 15 days respectively. How long will they take together, and how should a payment of ₹4,500 be shared?

   4 days. With total work 60 units, they do 6 + 5 + 4 = 15 units a day, so 60/15 = 4 days. Wages follow work done; they work the same days, so the ratio is 6 : 5 : 4: ₹1,800, ₹1,500 and ₹1,200.

   BeginnerQuick answer1 min read
5. A can do a job in 20 days. A works alone for 4 days, then B joins and together they finish the rest in 6 days. How long would B take alone?

   12 days. A works all 10 days and does 10/20 = half the job. B does the other half in 6 days, so B alone would need 12 days.

   IntermediateQuick answer1 min read
6. A can finish a job in 6 days and B in 12 days. If they work on alternate days, starting with A, in how many days will the job be finished?

   8 days. With 12 units of work, A does 2 units a day and B 1. Every 2-day cycle does 3 units, so 4 cycles (8 days) finish exactly 12 units.

   IntermediateQuick answer1 min read