Direct and Inverse Proportions-Important Questions

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

2.   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?

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

4.   The principal sanctioned a certain amount to the librarian to purchase some Mathematics books for the school library. She could buy 80 books casting Rs 90 each from the local book seller. There 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.

5.   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.

        

6.   A machine fills 540 bottles in six hours. How many bottles will it fill in five hours?

7.   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?

8.   In a PG House, the food provision for 20 persons is for 10 days. How long would the food provision last if there were 5 more persons in that PG house?