Tuesday, October 13, 2009

Some selected questions from PSLE 2009 Maths Examination Paper

WITH WORKINGS @
http://hongjun.blogspot.com/2009/10/psle-maths-question-with-workings.html

The below are some questions asked in this year's 2009 PSLE Maths paper.

Question 1
The above figure is a square. The angle question answer above is 150 degrees. Because the bottom triangle is equilateral triangle. (draw a circular curve through all 3 lines and they become the radii of the incomplete circle otherwise known as the arc)
360 - 60 = 300 degree
300 degree / 4 = 75 degree
75 degree x 2 = 150 degree

Question 2

6 friends decided to rent computers from 2pm to 4.30pm. While 4 of them were playing, the other two would watch. If the cycle continues, and each of them played for equal number of minutes, how many minutes will each person get to play? Ans: 100 minutes

Question 3

Mei and Lin were in a bicycle race. Mei was travelling at a constant speed of 20km/hr and they both did not change their speed. When Lin completed half the race, Mei was 3.5km ahead. Mei completed the race at 10.45am. What time did Lin complete the race? Ans: 11.06am

Question 4

Sally baked some cookies to sell. 3/4 of them were chocolate cookies and the remaining were almond cookies. After she sold 5/6 of chocolate cookies and 210 almond cookies, she had 1/5 of the cookies left. How many cookies did she sell? Ans: 960

Question 5

Jim bought some chocolates and gave half of it to Ken. Ken bought some sweets and gave half of it to Jim. Jim ate 12 sweets and Ken ate 18 chocolates. The ratio of Jim's sweets to chocolates became 1 : 7 and the ratio of Ken's sweets to chocolates became 1:4. How many sweets did Ken buy?. Ans: 68 sweets

Question 6

Curry puff shop sells puffs at $0.80 each. Offer:Buy 3 get 4th half price. If customer has $50, how many puffs can he buy if he buys as many as he can. Ans: 71 puff

Question 7

String of 2 big balloons is 90cm
String of 5 small balloons is is 1.2m
If both strings are of the same length, there would be 105 more small balloons than the big balloons. How many balloons are there altogether? Ans: 345

I shall post the workings for the above questions soon when I got the time.

5 comments:

  1. request for workings please.

    me and my frens can't get the answers!

    thanks!!

    ReplyDelete
  2. Question 4 answer is wrong. It is 1200.
    3/4 of 1200 is 900.
    1/6 of 900 is 150.
    1/4 of 1200 is 300.
    300 minus 210 equals 90.
    90 plus 150 equals 240.
    240 is 1/5 of 1200.
    Thus, this is the correct answer. 960 cannot be the answer.
    3/4 of 960 is 720.
    1/6 of 720 is 120.
    1/4 of 960 is 240.
    240 minus 210 equals 30.
    30 plus 120 equals 150.
    150 is 5/32 of 960, not 1/5.

    ReplyDelete
  3. You're the one who made the mistake of misinterpreting the question.

    1200 is the number of cookies baked.
    960 is the number of cookies sold.
    Question asks for number of cookies sold so Hongjun is correct here.

    ReplyDelete

Do provide your constructive comment. I appreciate that.