72% of 25 students are good in Mathematics. How many are not good in Mathematics?

A football team won 10 matches out of the total number of matches they played. If their win percentage was 40, then how many matches did they play in all?

If Chameli had Rs 600 left after spending 75% of her money, how much did she have in the beginning?

Find the ratio of the following:

(a) Speed of a cycle 15 km per hour to the speed of scooter 30 km per hour.

(b) 5 m to 10 km

(c) 50 paise to Rs 5

Convert the following ratios to percentages.
(a) 3 : 4 (b) 2 : 3