Quantitative Aptitude - Arithmetic Ability Questions

If a boat goes a certain distance at 30 km/h and comes back the same distance at 20 km/hr, what is the average speed (in km/hr) for the total journey?

A can paint a house in 55 days and B can do it in 66 days. Along with C, they did the job in 12 days only. Then, C alone can do the job in how many days?

The ratio of the present ages of Aman and Ankit is 2 : 1 and the sum of their present ages is 72 years. What will be the Aman's age (in years) after 6 years?

If the hour hand of a clock moves by 18 deg then by how many degrees does the minute hand move during the same time?

What number should be added to each of the numbers 35, 115, 53 and 165, so that the resulting numbers are in continued proportion?

16/3 =

A does 50% of a work in 12 days. He then calls in B and they together finish the remaining work in 8 days. How long B alone would take to complete the whole work?

Working together A and B can do a job in 40 days, B and C in 36 days and all three together in 24 days. In how many days can B alone do the job?