Prasanna invested certain amount in three different schemes X, Y and Z with the rate of interest 10% p.a, 12% p.a and 15% p.a respectively. If the total interest accrued in one year was Rs. 3200 and the amount invested in Scheme Z was 150% of the amount invested in Scheme X and 240% of the amount invested in Scheme Y, what was the amount invested in Scheme Y by Prasanna ?

A man reduces his travelling time by a fraction of 2/5, as a result the distance covered by the man is increased by 20%, find the percentage increase in the speed of the man ? 

The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased  ?

Rajeev start a business with Rs. 10000, Deepu joins him after 2 month with 20% more investment than Rajeev, after 2 month Shakti joins him with 40% less than Deepu. If the profit earned by them at the end of the year is equal to the twice of the difference between investment of Rajeev and ten times the investment of Shakti. Find the profit of Rajeev ?

The probability that a bowler bowled a ball from a point will hit by the batsman is ¼. Three such balls are bowled simultaneously towards the batsman from that very point. What is the probability that the batsman will hit the ball ?

In what ratio must a merchant mix two varieties of oils worth Rs. 60/kg and Rs. 65/kg, so that by selling the mixture at Rs. 68.20/kg, he may gain 10% ?

If the labour cost 20% of the cost of production and raw material cost 10% of the cost of production and the price on which article is sold is 20% above the cost of production. If the price of labour is increased by 40% and the price of raw material increased by 20% and rest other expenditure of cost remain constant. The industry thus decide to increase the selling price by 10%. Find the new profit percent  ?

Rajeev's age is four more than the age of Shilpa. The age of Shilpa can be obtained by subtracting four times her age 4 years ago from the four times her age after 4 years. What was Rajeev's age before 4 years ?