Tuesday, February 21, 2012

Monday, February 20, 2012

P6 Rate . P6 percentage

Hi Mr Chang, i have 2 questions which i cannot solve. Can you help me?
1) Henry can wash a car in 2 hours. Dolly can wash the same car in 3 hours. How long will it take Henry and Dolly to wash the same car together?
2) Jane and Iris has 255 sweets altogether. Jane had 15 more sweets than Iris. Jane gave away 25% as many sweets as Iris. She was left with twice as many sweets as Iris.
a) how many sweets did Iris give away?
b) how many sweets did Jane have in the end?


P6 ratio

A coin box contained only twenty-cent and fifty-cent coins in thr ratio of 4:5. When16 fifty-cent coins were taken out and replaced by some twenty-cent coins, the number of fifty-cent coins left in the box was 7/8 of the twenty-cent coins. The total value of all the coins remained the same. Find the sum of money in the coin box.
(question from Bo Zheng)

Monday, February 13, 2012

P6 fractions / percentage

[From Tao Nan paper. Via Chloe Phang from 6F(2012)]

Wednesday, February 8, 2012

Friday, February 3, 2012