What should come place of the question mark(?) in the following number series?
17, 18 , 26, 53 , 117, ? , 458

Ajay bought Rs.11,000 from a bank to buy a car at 12% simple Interest. If he paid Rs 6,600 as interest while clearing the loan, find the time for which the loan was given.

A sum of Rs. 6400 amounts to Rs. 6724 at 10% p.a. compounded quarterly. Find the time period.

The average age of x and y is 18 years. If z is equal to 9 years the average of x, y and z is -

Two friends A and B invest in a business in partnership. B borrows 20% of A’s salary, combines it with 60% of his salary and invests with A, who puts all of his remaining salary. One year later the ratio of profit of A and B is 5 : 3 respectively and B returns Rs. 21000 to A which he borrowed from him. What is the difference between salary of A and B?

A man rows to a place 35 km in distance and back in 10 hours 30 minutes. He found that he can row 5 km with the stream in the same time as he can row 4 km against the stream. Find the rate of flow of the stream? 

A man can swim to a place 120 km distant and come back in 35 hours. He finds that he  can swim 6 km against the stream in the same time as 8 km with the stream. Find the ratio of speed of man in still water to that of stream?