Quantitative Aptitude - Arithmetic Ability Questions

In a class of 39 students there are 26 girls. The average weight of these girls is 42 Kgs and average weight of the full class is 48 kgs. What is the average weight (in kgs) of the boys of the class?

Two numbers are 35% and 50% lesser than a third number. By how much percent is the second number to be enhanced to make it equal to the first number? 

If 2x + 6y = 3xy and 10x -­ 3y = 4xy, find x, y.

The flight fare between two cities is increased in the ratio 9:11. What is the increase (in Rs) in the fare, if the original fare was Rs. 18,000?

If x+1/x = 2, then the value of x7+2/x6 is equal to?

A person loses 75% of his money in the first bet, 75% of the remaining in the second and 75% of the remaining in the third bet and returns home with Rs. 2 only. His initial money was

If (4a-3)2=0,then the value of 64a3+12a+13 is

Of the four numbers whose average is 91, the first is 3/10 times the sum of other three. The first number is: