2008
7. In a concert hall, 𝟏𝟕 of the audience were children. 75% of the adults were women. There were 280 more women than children.
(a) How many women were there in the hall?
(b) During the interval, some men left the hall. As a result, 12% of the remaining audiences were men. How many men left the hall? NH08P48
8. At a farm, 40% of the animals are cows, 90% of the remainder are sheep and the rest are ducks. There are 56 more sheep than cows. After some cows died, 20% of the remaining animals at the farm are cows. How many cows are there left at the farm? SC08P48
9. There were 2200 children at a carnival. 56% of them were boys. How many more boys had to join the carnival so that the percentage of boys would increase to 60%? SN08S41
10. The number of blue paper clips to the number of white paper clips in a box was 5 : 3. Ryan removed 24 blue paper clips and the ratio of the number of blue paper clips to the number of white paper clips became 7 : 9. Find the total number of paper clips left in the box. SN08C38
11. Mark had some red and blue marbles in the ratio 5 : 3. After losing 96 red marbles, the ratio became 3 : 5. How many red marbles did Mark have at first? RY08P36
12. 20% of the people at the auditorium are adults. 25% of the children are boys. There are 80 fewer boys than girls. Assuming that the number of adults remain the same, how many girls must leave so that the number of adults is 50% that of the number of girls in the auditorium? NH08C47
13. A florist had some roses, tulips and carnations at first. For every 2 roses that were sold, 3 tulips were sold. For every 5 carnations that were sold, 7 tulips were sold.
(a) Find the ratio of the number of roses to the number of tulips to the number of carnations the florist had at first.
(b) After 24 roses were thrown away as they had wilted, 𝟏𝟕 of the remaining flowers were roses. How many tulips were there? NY08S47
14. There were twice as many flowers in Box A than in Box B. The ratio of the number of lilies to the number of roses in Box A is 3 : 2. The ratio of the number of lilies to the number of roses in Box B is 2 : 3. When 6 roses were transferred from Box B to Box A, the ratio of the number of lilies to the number of roses in Box B became 3 : 4.
(a) How many flowers were there in Box A after the transfer?
(b) What was the ratio of the number of lilies to roses in Box A after the transfer? MB08C44
15. Mary and Jason each have some money. If Mary spent $80 per day and Jason spent $40 per day, Mary will have $500 left when Jason has spent all his money. If Mary spent $40 per day and Jason spent $80 per day, Mary will have $1100 left when Jason has spent all his money. What is the amount of money Jason has? AC08P41
2009
16. 60% of the people at a water theme park were adults. 75% of the remainder were boys. There were 140 more adults than girls. More children came to the park, after which 60% of the people in the park were children. How many more children came to the park? NH09P17
17. The ratio of the number of girls to the number of boys in the RosythAniManga Club last year was 3 : 2. When 24 girls joined the club this year, the ratio became 11 : 6. Find the number of girls in the club this year. RY09P13
18. At a shop, the ratio of the number of stalks of roses to the number of stalks of carnation was 4 : 5. Mrs Tan sold 176 stalks of carnations and was left with thrice as many stalks of roses as carnations. How many stalks of carnations did she have at first? SN09S09
19. The ratio of the number of apples to the number of oranges in a basket is 4 : 5. When Mother took 15 apples out to make apple pies, the ratio of the number of apples to the number of oranges became 3 : 10. How many fruits were there in the basket at first? RS09S07
20. At a party, only 49 of the invited guests came. The ratio of the number of women to the number of men present was 3 : 4. If 80 more men turned up for the party, the number of men would be twice the number of women. How many guests were invited? AT09C15
21. Mrs Lim had 50 stamps. 60% of them were local stamps and the rest were foreign stamps. After she used some local stamps, the percentage of stamps that were local stamps decreased to 20%. How many local stamps had she left? SC09P09
22. Tom’s savings was 23 of Jane’s savings. After Jane had spent $180, her savings became 34 of Tom’s savings. How much did Tom save? RG09S09
23. Mrs Chan had some beads. 38% of the beads were red and the rest were yellow. After she had bought some more red beads, the percentage of red beads increased to 84% of the total number of beads. How many red beads did she buy if she had 496 yellow beads? NY09S09
24. At the start of a soccer match, the number of female spectators was twice the number of male spectators. After 230 female spectators left the match, the number of male spectators was thrice the number of female spectators. What was the total number of spectators at the start of the match? RY09C07
25. The ratio of the number of boys to the number of girls in School A is 4 : 1. The ratio of the number of boys to the number of girls in School B is 2 : 3. School A had twice as many pupils as School B.
(a) What is the ratio of the number of boys in School A to the number of girls in School B? (b) After 30 girls left School A to join School B, the ratio of the number of boys to the
number of girls in School B is now 5 : 8. How many girls are there in School B now? NY09C16
26. There were some prizes to be won at a Shop and Win contest. 35% were cash prizes and the rest were household items. Some cash prizes were given out and the percentage of cash prizes decreased to 22%. If there were 54 more household items than cash prizes at first, find the number of cash prizes being removed. SN09S15
27. The number of boys to the number of girls in Happy Kindergarten was 3 : 5. The number of boys to the number of girls in Merry Kindergarten was 4 : 5. Both kindergartens had the same number of boys. When 10 girls from Happy Kindergarten joined Merry Kindergarten, the ratio of the number of boys to the number of girls in Happy
Kindergarten became 2 : 3. Find the total enrolment of the 2 kindergartens. SN09S17
28. Sparkles Jewellery Shop sold diamonds, rubies and emeralds. 35 of the gemstones were diamonds. There were 168 fewer rubies than diamonds. The ratio of the number of rubies to the number of emeralds was 7 : 3. After some rubies were sold, 30% of the remaining gemstones in the shop were rubies and emeralds.
(a) How many rubies were sold?
(b) Find the percentage decrease in the number of gemstones. Leave your answer as a fraction. SN09S18
29. Country A and Country B took part in a Youth Game. From Country A, the ratio of the number of male supporters to the number of female supporters is 5 : 6. From Country B, the ratio of the number of male supporters to the number of female supporters was 1 : 3. The total number of supporters from Country A is 1
4 of the total number of supporters
from Country B.
(a) What is the ratio of the number of female supporters from Country A to the number of female supporters from Country B? Express your answer in the simplest form. (b) After 4985 male supporters from both countries left, the percentage of all the
female supporters became 78%. How many more male supporters from Country B than Country A were there at first? PL09P16
30. Audrey and Belle have some money each. If Audrey spends $18 and Belle spends $24 each day, Audrey will still have $25 left when Belle has spent all her money. If Audrey spends $13 and Belle spends $30 each day, Audrey will still have $139 left when Belle has spent all her money. How much money do they have altogether? NY09S14
2010
31. Kenji had 2
5 of the total amount Jace and he had. After Jace spent $45, she had 1
4 of the
amount Kenji had. How much did Kenji have? RS10P01
32. JiaHui had 350 jelly beans. 52% of them were orange flavoured. She ate some of the orange flavoured jelly beans and the percentage of orange flavoured jelly beans decreased to 44%. How many orange flavoured jelly beans did JiaHui eat? SC10P08
33. Kelly had 5100 beads. 20% of them were red. After Carol gave her some more red beads, the percentage of red beads increased to 40%.
(a) How many red beads did Kelly have at first?
(b) How many red beads did Carol give Kelly? RY10S15
34. There were an equal number of red and white roses in a flower shop. After 46 red roses had been sold, three times as many white roses as red roses were left. How many roses were there in the shop at first? AT10C06
35. Ali had some green and blue pens. 20% of his pens are blue. He then bought 45 blue pens and the percentage of his blue pens increased to 50%. How many pens did he have altogether at first? RS10P09
36. Mr Gopal had 210 red and blue pens of which 20% were red. He bought some more red pens and the percentage of red pens was increased to 30%. How many red pens did he buy? RY10P06