Quantitative Aptitude - Arithmetic Ability Questions

A ladder 13 m long reaches a window which is 12 m above the ground on side of a street. Keeping its foot at the same point, the ladder is turned to the other side of the street to each a window 5m high, then the width of the street is :

The amount (in Rs) received at 10% per annum compound interest after 3 yrs is Rs 1,19,790. What was the principal?

A boat cover row 12 km upstream in 4 hours and can cover the same distance downstream in 3 hours. What is the speed (in km/hr) of the boat in still water?

Of the 3 numbers whose average is 40, the first is 1/3 rd the sum of other 2. What is the first number?

The mid points of AB and AC of the Δ ABC are P and Q respectively. If PQ = 6 cm, then the side BC is

A trader buys 500 kgs of cotton for Rs 9,000. 10% of this cotton is spoiled due to rain. At what rate (Rs/Kg) should he sell the rest to earn 10% profit?

The mean of 12 observations is 15. One more observation is included and the new mean becomes 16. The 13th observation is

A solid cube is cut into 27 identical cubes. What is the percentage increase in the total surface area?