Chang's Math blog

Saturday, July 23, 2011

Timothy wants to buy a skateboard. It costs $17.25. Every week he saves $1.20 more than the week before. After saving for a number of weeks, he bought the skateboard.

(a) What is the least number of weeks he needs to save enough to buy the skateboard?

(b) How much of his savings did he have left after buying the skateboard?

Do we assume that Timothy started saving $1.20 on the first week? The question did not state how much Timothy saved on the first week.

(fr: JH, 23/7/11)

Wednesday, May 11, 2011

P5 Whole numbers

Sandra had twice as many apples as oranges at first. She removed 4 apples and 3 oranges each time. In the end, there were 18 apples and 1 orange left. How many fruits did Sandra have at first?

My solution:

https://docs.google.com/document/pub?id=1EaD59T5uGgvxYgr-aFAMM6oqmF12fmQoBdd8Z4H_-20

Sunday, May 8, 2011

Tuesday, May 3, 2011

Monday, May 2, 2011

P5 Fraction, (2 variable prob)

J had 933 chairs n tables at first. After he sold 2/5 of the tables n 5/8 of the chairs, he had 459 tables n chairs left. How many tables did he sell?
(ans: 194?)

Saturday, April 30, 2011

>> 1)In Sunshine Home,the ratio of the number of men to the number of women is 4:1. In Joyful Home,the ratio of the number of men to the number of women is 2:3. Sunshine Home has twice as many people as Joyful Home.
>> (a)Find the ratio of the number of men in Sunshine Home to the number of women in Joyful Home.
>> (b)After 40 women left Sunshine Home to join Joyful Home,the ratio of the number of men to the number of women in Joyful Home becomes 1:2. How many women are there in Joyful Home in the end?
>>
>>
>> 2)4boys and 2 girls sold 2400 tickets at a fun fair. The 2 girls sold twice as many tickets as the 4 boys. Each boy sold the same number of tickets. The first girl sold 3 times as many tickets as the second girl.
>> (a)How many tickets did each boy sell?
>> (b)How many tickets were sold by the first girl?
>>
>>
---
Q1
> (a) 8:3
> (b) 160
>
> Q2
> (a) 200
> (b) 1200

Friday, April 22, 2011

P6 ratio, volume **

P6 fraction **

Thursday, April 14, 2011

Fractions (fr: Corrine Poh, 5C10)

Mrs Ching had a total of 400 apples and mangoes in her shop. When 3/8 of the apples were sold, the number of aples left was 120 more than the number of mangoes. How many mangoes were there in the shop?

[Answer: 80 Mangoes]