The number of children in a camp is x and their average weight is 20 kg. If 5 children each weighing 12 kg, join the camp or if 10 children each weighing 21 kg leave the camp, the average weight in both the cases remain the same. The value of x is

Reshma sells an article to Rekha at 37.5% profit, Rekha sells it to Madhu at \(9\frac{1}{11}\)% profit. Again Madhu sells it to Mitu at 25% loss. If Mitu pays Rs. 342 for the article, then what is the cost price of the article to Reshma?

In a 120 litre of solution of Acid and water, acid is 75%. A person takes out 20 litres of this solution and added 16.2 litres of acid and 3.8 litres of water in the remaining solution. What is the percentage of water in the final solution?

The marked price of an article is 20% more than the cost price. If the article is sold at a discount of 15% on its marked price, then the gain percent is

Twelve men and 5 women can complete a work in 2 days whereas 4 men and 3 women can complete the same work in 5 days. In how many days can 8 men complete the work?

A sum amounts to Rs. 9680 in 2 years and to Rs. 10648 in 3 years respectively at compound interest. What will be the amount if the same sum is invested for \(1\frac{2}{5}\) years at the same rate of compound interest?

A and B are inversely proportional to each other and are positive. If A increases by 100%, then B decreases by

Suman saves 10% of her monthly salary. Now her expenditure increases by 30% and savings increases by 50%. The present increase in her salary is

Four pipes A, B, C and D can fill a tank with water in 15, 20, 30 and 60 hours respectively. Pipe A is opened at 4 a.m., B at 5 a.m., C at 6 a.m. and D at 7 a.m. When is the tank filled up completely?