Quantitative Aptitude - Arithmetic Ability Questions

Product of 9b2, 3a2 and 4ab is

A can do 1/3rd of a work in 5 days and B can do 2/5th of this work in 10 days. Both A and B, together can do the work in

The average of 21 numbers is 12. The average of the first 11 numbers is 9 and the average of the last 11 numbers is 15. What is the value of the middle number?

If a is positive and a2+1a2 = 7, then a3 + 1a3 = ?

A car travels a certain distance at 34 km/h and comes back at 66 km/h. What is the average speed for total journey?

From an external point two tangents to a circle are drawn. The chord passing through the points of contact subtends an angle72° at the centre. The angle between the tangents is?

What is the value of (cos45° + 1/3) ?

Expand and simplify (3x + 2)2*(4x -­ 3) -­ (2x3 - 9x2 + 12x -­ 24)