she had 30 candies left. How many candies did she have at first ?
2. During a school assembly, the ratio of the number of girls to the number of boys was 6 : 7. If 63 girls left the school hall, the new ratio of the number of girls to the number of boys became . How many pupils were there in the school hall at first ?
3. Tap A can fill up an empty tank in 20 minutes.
Tap B can empty the same tank completely filled with water in 12 minutes.
Both taps are turned on at the same time when the tank is half-filled with water.
How long will it take for the tank to be totally emptied?
4. A cuboid has a rectangular base of perimeter of 64 cm. The ratio of its length to its breadth of the base is 5:3. The volume of the cuboid is 2400 cm³.
Find its height.
5. Raju earns a monthly salary of $ 4 500. He spends 1/5 on food and gives 2/3 of the remainder to his mother. He will save the remaining sum of his salary. How much will he save after 1 year?