Maths worksheets for challenging problem sums

Related Skills
Skill Involving Changing quantities

* Practice for skill involving changing quantities

1) A shopkeeper sold 837 candles on the first day. The next day, he sold 60% of the remaining candles. As a result, the number of candles left became 17 of the number of candles he had at first. How many candles did the shopkeeper have at first?

Ans :- 1302.

2) There were 2108 pupils in a school last year. This year the number of boys has been reduced by15 and the number of girls has been reduced by 0.25. There are as many boys and girls in the school now.
(a) How many pupils are in the school now?
(b) How many boys were in the school at first?

Ans :- a) There are 1632 pupils
b) There were 1020 boys at first..

3) Ray's collection of Malaysia stamps to Singapore stamps was in the ratio 5 : 1. After he had given his cousin 30 Malaysia, he had 2 fewer Malaysia stamps than Singapore stamps. How many stamps did he have at first?

Ans :- He had 42 stamps at first.

4) Mdm. Fatimah gave 8% of her monthly salary to charity. When her salary was decreased by $100, she continued to give the same percentage of her salary to charity. If the charity received $248 monthly from Mdm. Fatimah after the decrease in her salary, what was Mdm. Fatimah's salary before the decrease?

Ans :- $3200.

5) Linda and Paul shared some marbles in the ratio 3 : 2. In a game, Paul lost half of his marbles to Linda. After the game, Linda had 18 marbles more than Paul. How many marbles did Linda have after the game?

Ans :- 24 marbles.

6) At first, Sarah had 47 of the number of marbles Jack had. When Sarah received 36 marbles from Jack, both had the same number of marbles.
(a) How many more marbles did Jack have than Sarah at first?
(b) How many marbles were there altogether?

Ans :- a) 72 more marbles
b) 264 marbles .

7) There are 160 red marbles and some blue marbles in a box. If
38 of the blue marbles is taken out of the box and 50 new red marbles are put into the box, the ratio of the number of red marbles to the number of blue marbles becomes 7:9. How many blue marbles are there in the box?

Ans :- 432.

8) Boxes A and B each contained some books. After 110 of the books in Box B was taken out and put into Box A, the ratio of the number of books in Box A to the number of books in Box B was 4:3. What was the ratio of the number of books in Box A to the number of books in Box B at first?

Ans :- 11: 10.

9) The ratio of Raju's mass to John's mass is 5:6. If Raju's mass increased by 4 kg and John's mass is decreased by 2 kg, Raju will have the same mass as John. What is Raju's original weight?

Ans :- 24 kg.

10) A box of beads was shared between Ali and Mingfa in the ratio 3: 2. After Ali gave ½ of his share to Mingfa, Mingfa had 20 more beads than Ali. How many beads did Ali give to Mingfa?

Ans :- 15 beads.