900 gm of sugar solution has 40 % of sugar in it. How much sugar should be added to make it 50% in the solution?

The following bar graph gives the annual rate inflation in percentage for 1975 and 1987. Study the graph and answer the following questions. 

The change in rate of inflation was least in which of the following?

A Man wants to plant trees in his garden in rows in such a way that the number of trees in each row is the same. If there are 24 rows, the number of trees in each row is 42. If there are 12 more rows find the number of trees in each row?

Dhoni buys spirit at Rs.60/liter and added some water to it and then sells it at Rs.75 per liter, what is the ratio of spirit to water if his profit in this deal is 37.5 %?

Ravi wants to sell a mobile phone at a profit of 20%. If he bought it at 10% less and sold it at Rs. 1200 less, but still he gained 20%. The cost price of the mobile is:

Ram and Syam together have Rs. 1210. If 4/15 of Ram′s amount is equal to 2/5 of Syam′s amount, how much amount does Syam have?

A car moving at 40 km per hour covers a distance in 6 hours 15 minutes. If it travels the same distance at 50 km per hour how long will it take to cover the distance?

In an examination, 1400 boys and 700 girls appeared out of which 40% of the boys and 50% of the girls failed. Find the percentage of candidates who passed.

The mean of marks secured by 45 students in division A of class X is 69, 65 students of division B is 65 and that of 50 students of division C is 63. Find the mean of marks of the students of three divisions of Class X.

If Saroj earns 24% more than Manoj. What percent less does Manoj earn than Saroj?

The sum of the ages of husband and wife at present is 100. Ten years ago the ratio of their ages was 9:7. What is the age of the husband?