Quantitative Aptitude - Arithmetic Ability Questions

Some girls can do a piece of work in 18 days. In how much time (in days) two times the number of such girls will complete thrice of the work?

If ax - 4y = -6 has a slope of -3/2. What is the value of a?

What is the reflection of the point (5 , -1) in the line y = 2?

tan(A/2) is equal to

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

The ages of A and B differ by 16 years. If 6 years ago, the elder one was 3 times as old as the younger one, find the present age of the younger between A and B?

The average height of A, B and C is 148 cm. If the average height of A and B is 136 cm and that of B and C is 125 cm, then what is the height (in cm) of B?

If 3P/7 = 4Q/11, then what is the ratio of P and Q respectively?