If cosec 39°= x, the value of $$ {1\over {cosec^{2}{51°}}} +sin^{2} 39^{°}+tan^{2}{51^{°}}-{1\over {sin^{2}{51^{°}}}{Sec^{2}{39^{°}}}}$$ is-

What will be come in place of question mark(?) in the following number series?
3, 22, ? , 673, 2696, 8093

A sum becomes 5 times of itself in 3 years at compound interest (interest is compounded annually). In how many years will the sum becomes 125 times of itself?

If the ratio of speed of train, car and bus is 6:5:3 and bus cover a distance of 240 km. in 4 hours. What is the difference between speed of the train and car?

By what fraction selling price ( S.P. ) must be multiplied to get the cost price ( C.P. ) if the loss is 20%? 

In how many years will be Rs. 2,000 amounts to Rs.2,420 at 10% per annum compound interest ?

In a shop shirt are usually sold at 40% above the cost price. During a sale, the shopkeeper offers a discount of 10% off the usual selling price. If he man ages to sell 72 shirts for ₹ 13,608 then his cost price per shirt, ( in ₹) is 

A mobile plan costs Rs. 32 for 6 minutes. What is the approximate cost, in rupees, for 4 minutes?