What will come in place of the question mark (?) in each of the following series?

15     18    16   19     17    20    ?

If Rs 1380 is divided into A, B and C in such a way that A gets 5 times B's share and 3 times C's share. Then what is the value of C parts?

The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 9 % per anmum is Rs . 405 The sum is

The median of the number 14, 12, 12, 16, 13 and 18 is:

Profit after selling a commodity for 524 is the same as loss after selling it for Rs. 452. The cost price of the commodity is 

A clock runs fast by 5 mins per hour. If the clock was set right at 12 noon and the clock shows 6.30 p.m. now, what is the right time? 

If a clock strikes 12 in 33 seconds, it will strike 6 in how many seconds?