Quantitative Aptitude - Arithmetic Ability Questions

A person borrows some money for 8 years at a rate of simple interest. If the ratio of principal and total interest is 5 : 8, then what is the rate ( inpercentage) of interest?

A train crosses a 550 m long platform in 36 seconds. How long was the train if it was travelling at the speed of 70 kmph?

9 hrs after a goods train passed a station, another train travelling at a speed of 72 km/hr following that goods train passed through that station. If after passing the station the train overtakes the goods train in 3 hours. What is the speed of the goods train?

In a college, the ratio of boys to girls is 29 : 33 respectively. When 142 more boys join the college, this ratio becomes 21 :19. How many more girls should join the college to make the number of boys and girls equal?

What is the value of tanπ4+A×tan3π4+A ?

If 9x2 + 16y2 = 60 and 3x + 4y = 6, then the value of xy is

If x + 1/x = 6, then value of x2 + 1/x2 is

If a + b = 10 and ab = 21, then the value of (a - b)2 is