Quantitative Aptitude - Arithmetic Ability Questions

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A, B and C can complete a work in 20, 24 and 30 days respectively. All three of them starts together but after 4 days A leaves the job and B left the job 6days before the work was completed. C completed the remaining work alone. In how many days was the total work completed?

A girl walking at the speed of 2 km/hr covers a certain distance in 7 hours 30 minutes. If she covers the same distance by cycle in 5 hours, then what is the speed (in km/hr) of cycle?

The average age of 27 students of a class is 22. If the age of the teacher is also added to their ages, then the average increases by one. Find the age of the teacher.

The compound interest on Rs. 64,000 for 3 years, compounded annually at 7.5% p.a. is Rs. 64,000

On dividing 221a2b2 by 13b2, we get _____.

What is the distance between the points (4,­-8) and (­-2,0)?