6 pipes are required to fill a tank in 1 hour 20 minutes. How long will it take if only 5 pipes of the same type are used?

There are 100 students in a hostel. Food provision for them is for 20 days. How long will these provisions last, if 25 more students join the group?

If 15 workers can build a wall in 48 hours. How many workers will be required to do the same work in 30 hours?

The principal sanctioned a certain amount to the librarian to purchase some Mathematics books for the school library. She could buy 80 books costing Rs 90 each from the local book seller. Then she approached to the publisher who offered her a 20% discount. Find the number of copies of Mathematics books which she could buy from the publisher for the sanctioned money.

Observe the following table where x and y are directly proportional.

Find the unknown quantities.

A mixture of paint is prepared by mixing 1 part of green pigments with 6 parts of the base. In the following table, find the parts of base needed to be added.

5 kg of sugar contains 19 x 10⁶ crystals. How many sugar crystals are there in 2 kg of sugar?

Jagmeet has a road map with a scale of 1 cm = 20 km. He drives on a road for 72 km. What would be his distance covered in the map? 

A contractor estimates that 5 persons complete a task in 4 days. If he uses 4 persons instead of 5, how long should they take to complete the task?

A factory requires 49 machines to produce a given number of articles in 54 days. How many machines would be required to producte the same number of articles in 63 days?