Quantitative Aptitude - Arithmetic Ability Questions

If x + (1/x) = 2, then what is the value of x64 + x121?

In a committee there are 15 members. If two members whose ages are 45 years and 55 years are replaced by the two new members, then average age of 15 members is increased by 2 years. What is the average age (in years) of the new members?

The original price of a TV set is Rs. 6,000. If the price is discounted by 20% and then raised by 10% for service contract, the price charged by the shopkeeper is

To go a distance of 40 km upstream a rower takes 8 hours while it takes her only 5 hours to row the same distance downstream. What was the rower's speed in still water?

If the simple interest on Rs. 400 for 10 years is Rs. 280, then rate of interest per annum is

If a + b = 4 and ab = 3, then what is the value of a3 + b3?

If 3x + 5y + 7z = 49 and 9x + 8y + 21z = 126, then what is the value of y?

In the given series of numbers how many 7's are there which are immediately followed by 9 and immediately not preceeded by 5 ?