Quantitative Aptitude - Arithmetic Ability Questions

Meghnad can do a piece of work in 45 hours. If he is joined by Jayshri, who is 50% more efficient, in what time will they together finish the work?

A man covered a certain distance by a train running at the speed of 50 km/hr and covers the same distance back by walking at the speed of 5 km/hr. Ifthe whole journey took 5 hours 30 minutes, then what was the distance (in km) of one side?

What is the largest 4 digit number which is exactly divisible by 81?

Bipul is 16 years younger than Saibal. 12 years hence, Saibal's age will be 1.5 times that of Bipul. Saibal is now ___ years old.

What is the value of (91 + 92 + 93 + ......... +140)?

What is the value of [(cos 7A + cos 5A)÷(sin 7A – sin 5A)]?

In a bag the ratio of red balls to green balls is 4 : 9. If 6 more green balls were added to the bag, the ratio of red balls to green balls would become 1 : 3. How many red balls are there in the bag?