If a box of pens is given to 25 children, they will get 2 pens each. How many would each get, if the number of children is reduced by 10? 

4 A bus travels 40kms in 30minutes. If the speed of the bus remains same, how far can it travel in 3 hrs? 5 A contractor estimates that 5 persons could plumb Ravi's house in 8 days. If he uses 6 persons instead of 5, how long should they take to complete the job. 7 A batch of tablets were packed in 10 boxes with 6 tablets in each box. If the same batch is packed using 12 tablets in each box. How many boxes would be needed? 8 In a toy company, it requires 36 machines to produce a car toys in 54 days. How many machines would be required to produce the same number of car toys in 81 days?