Quantitative Aptitude - Arithmetic Ability Questions

A boat covers 143 km upstream in 13 hours and the same distance downstream in 11 hours. What is the speed (in km/hr) of the boat in still water?

What is the value of xy if x - y = 3 and x2+y2=15?

The sum of 4x + 3y ­ 7z, x ­ y ­ z and ­2x ­ 3y + 4z is

The value of Cot17°Cot73°Cos222° + 1Cot17°Sec268° is

Rohit buys a ball for Rs 450 and sells it. Rohit gives two successive discount of 20% and 5% to the customer. What will be the selling price (in Rs) of the ball?

A sum of Rs 6000 becomes Rs 7200 in 2 years, when invested in a scheme of simple interest. If the same sum is invested in a scheme of compound interest with same yearly interest rate (compounding of interest is done yearly), then what will be the amount (in Rs) after 3 years?

Two numbers are 50% and 90% lesser than a third number. By how much percent is the second number to be enhanced to make it equal to the first number?

In the first 43 overs of a cricket match, the run rate was 5 runs/over. Calculate the required run rate in the remaining 7 overs to reach the target of 285 runs?