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## Saturday, May 09, 2009

### Rosyth Sch 2006 PSLE Math Prelim Q46

At a fun fair, there were 49 more children than women. There were 3/5 as many men as women. Given that the number of women was 25% of the total number of people at the fun fair, how many people were at the fun fair?

Solution

Men ----- 3 units
Women ----- 5 units
Children ----- 5 units + 49
Total ----- 13 units + 49

(Women) 5 units ----- 25%
1 unit ----- 25% divided by 5 = 5%
13 units ----- 13 x 5% = 65%

Remaining 49 people ----- 100% - 65% = 35%
35% ----- 49 people
(35% divided by 7)= 5% ----- (49 divided by 7) = 7
5% ----- 7
(5% x 20) = 100% ----- (7 x 20) = 140
100% ----- 7 x 20 = 140

Answer: There were 140 people at the fair.

#### 13 comments:

xiang er said...

Organisms exhibit different behaviours in response to the amount of light in their surroundings. Which one of the following statements about such behaviours of organisms is false?

1.Tigers hunt during the day
2.Eagles are more active in the dark
3.Earthworms prefer to be in the dark
4.Grass does not grow well in the shade

Anonymous said...

Meet: At 0900 h, car A left Town X for Town Y travelling at a speed of 100 km/h.An hour later, car B left Town Y for Town X at the speed of 90 km/h.The distance between the two towns is 670 km.AT what time did the two cars meet?

Anonymous said...

Pens: Thks,GAAM.How about this one? Sorry, I had used algebra to solve and got 360 pens coz couldn't think of another way. A shopkeeper had some red and blue pens.The number of red pens was 25% of the total number of pens.After selling away 30 red pens and 30 blue pens, the number of red pens became 25% of the number of blue pens left.How many pens did he have at first?

Red & Blue: R : B = 1 : 3 = 2 : 6 = 3 : 9. RN : BN = 1 : 4 = 2 : 8. 1 u --> 30. 12 u --> 12 x 30 = 360 pens.

Anonymous said...

Pens: Thks,GAAM.How about this one? Sorry, I had used algebra to solve and got 360 pens coz couldn't think of another way. A shopkeeper had some red and blue pens.The number of red pens was 25% of the total number of pens.After selling away 30 red pens and 30 blue pens, the number of red pens became 25% of the number of blue pens left.How many pens did he have at first?

Red & Blue: R : B = 1 : 3 = 2 : 6 = 3 : 9. RN : BN = 1 : 4 = 2 : 8. 1 u --> 30. 12 u --> 12 x 30 = 360 pens.

Anonymous said...

Race: Ali and Tom competed in a race. Ali ran at the speed of 12 km/h during the first half of the journey and 4 km/h during the second half of the journey.Tom ran at the average speed of 8 km/h throughout the journey.Who won the race? My method is to give a dummy distance for the race say 24 km and work out the time taken for both Ali and Tom.Is this acceptable, pls advise? BTW, Tom won the race.

No assumption required: When travelling at 4 km/h, Ali only covered half the distance when Tom completed the race at 8 km/h. So Tom won.

Anonymous said...

Why are the eyes of a lion set in the front of its head rather than on the sides?

Anonymous said...

A box of sweets is shared equally among Jane, Ahmad and Samy.Jane divided her share into 3 equal packets.Ahmad divided his share into 4 equal packets.Samy divided his share into 6 equal packets.The total number of sweets in 2 of Jane's packets, 3 of Ahmad's packets and 3 of Samy's packets is 138.What is the total number of sweets in the box?

There were 121 animals in a farm.8/9 of the cows and 4/5 of the ducks were sold.In all, 104 animals were sold.How many ducks were there in the farm at first?

Last week, Belinda visited a travel exhibition.At Hall A, she paid \$3 entrance fee and spent half her money on the deposit for a travel package she took up.She left Hall A and spent \$15 on lunch.Then she paid another \$3 to visit Hall B.Inside Hall B she spent half of what she had left on a travel guidebook.After leaving Hall B, she had \$50 left.How much did she have before she visited the travel exhibition?

Hazel took 2/3 of her savings to go shopping.After spending 2/5 of the money on a watch and 1/6 of the remainder on a dress, she still had \$ 534 left.How much was her savings?

The figure below shows a fish tank A, 35 cm long, 28 cm wide and 56 cm high which is filled with water to a depth of 34 cm.Water is pumped out from the fihs tank until it is half empty into Container B which is 20 cm long, 16 cm wide and 27 cm high.Find the water level in Container B.Give your answer to 1 decimal place.

There were 600 animals on Mr Tan's farm.30% of the animals were ducks and the rest were chickens.He bought some ducks which made up to 40% of the animals on the farm.How many ducks did he buy?

The ratio of a length of a parallelogram to that of its breadth is 9:7. The breadth is shorter than the length by 258.6 cm.Find the perimeter of the parallelogram.

A shopkeeper bought 8 sacks of red beans, each weighing 3.5 kg.He repacked the beans equally into small packet of 500g each and sold them at \$ 1.75 per packet.How much money did he collect after selling all the packets?

Anonymous said...

Is the Chat Box expired?

Anonymous said...

A red cube is completely filled with yellow cubes of the same type. Each yellow cube has a volume of 64 square cm. Each yellow cube is completely filled with identical green cubes. The ratio of the length of the sides of the red cube to the yellow cube to the green cube is 6:2:1. How many cubes are there altogether?

green leaf said...

Green --- 1
yellow --- 27
Red --- 108

Total --- 136

Excel Eduservice said...

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Cubes said...

I am afraid 136 is not correct.
Green -- 1
Yellow -- 27 [= 1 x 3 x 3 x 3]
Red -- 216 [= 27 x 2 x 2 x 2]
Total = 244

green leaf said...

Hi Cubes

You are right.Thank you for the correction.