Quantitative Aptitude - Arithmetic Ability Questions

If x = 313- 3-13, then 3x3 + 9x value is

Number of composite numbers lying between 67 and 101 is

A school has 8 periods of 45 minutes each, every day. How long will each period be if the school has to have 9 periods everyday, assuming the working hours to be the same?

A thief is stopped by a policeman from a distance of 250 metres. When the policeman starts the chase, the thief also starts running. Assuming the speed of the thief as 5 km/h and that of police man as 7 km/h, how far the thief would have run, before he is over ­taken?

A is twice as good as B and together they finish a piece of work in 16 days. The number of days taken by A alone to finish the work is

If Sec θ = 5/3, then what is the value of Cosec θ?

If P = 7 + 4√3 and PQ = 1, then what is the value of 1/P2 + 1/Q2?

If 9x2 + 16y2 = 60 and 3x + 4y = 6, then the value of xy is