The ratio of number of boys and girls in a class is 2 : 3. The average weight of boys and girls in the class is 18 kg and 21 kg respectively. What is the average weight (in kgs) of all the boys and girls together?
Profit obtained on selling an article for Rs 540 is equal to the loss incurred on selling the article for Rs 370. If selling price is Rs. 910, then what is the profit percentage?
If a boat goes upstream at a speed of 24 km/hr and comes back the same distance at 40 km/hr. What is the average speed (in km/hr) for the total journey.