Q&A - P3 Math

[allcc6]

MathIzzzFun:

Q2. Mr Tan is 42 years old and his son is 8 years old now. In how many years time will Mr Tan be twice as old as his son?

The age difference will remain the same.

Age difference = 42 - 8 = 34

When Mr Tan is twice as old as his son, and since the age difference is 34, Mr Tan will be 2 x 34 = 68
68 - 42 = 26 --> Mr Tan will be twice his son's age in 26 years' time.

cheers.

Can anyone advise the steps if question is changed to :

Mr Tan is 42 years old and his son is 8 years old now. In how many years time will Mr Tan be three times as old as his son?

[mrswongtuition]

allcc6:

MathIzzzFun:

Q2. Mr Tan is 42 years old and his son is 8 years old now. In how many years time will Mr Tan be twice as old as his son?

The age difference will remain the same.

Age difference = 42 - 8 = 34

When Mr Tan is twice as old as his son, and since the age difference is 34, Mr Tan will be 2 x 34 = 68
68 - 42 = 26 --> Mr Tan will be twice his son's age in 26 years' time.

cheers.

Can anyone advise the steps if question is changed to :

Mr Tan is 42 years old and his son is 8 years old now. In how many years time will Mr Tan be three times as old as his son?

KEY CONCEPT: The age difference does not change.

Their age difference is 42 - 8 = 34 years.

Mr Tan [---][---][---]
Son `` [---]<--34-->

2 units --> 34
1 unit --> 34/2 = 17

17 - 8 = 9
Ans: In 9 year's time

[tracywham]

Hi, can i have some guidance using "models" to solve this question please. Thank you.


Clarence had 4 times as much as John. After spending $230 on clothes, Clarence still has $160 more than John. How much money did Clarence have at first?

The answer is $520.

[BigDevil]

http://i46.tinypic.com/2n6rert.jpg\">

[tracywham]

Oic.... i understand now... thanks for your illustration too...sometimes i just get confused with the before and after concept....

[Cher2101]

Hi can you please help me on these 2 questions.


1). Bao Ming wants to buy 6 shirts but he is short of $7. If he buys 5 shirts, he will have $11 left. How much money does Bao Ming have?

2). Ben had twice as many books as Eve. If Ben gave Eve 20 books, Ben will have 10 more books than Eve. How many books do they have altogether?

[SAHM Chew]

Cher2101:

Hi can you please help me on these 2 questions.


1). Bao Ming wants to buy 6 shirts but he is short of $7. If he buys 5 shirts, he will have $11 left. How much money does Bao Ming have?

2). Ben had twice as many books as Eve. If Ben gave Eve 20 books, Ben will have 10 more books than Eve. How many books do they have altogether?

1) $11 + $7 = $18
$18 x 5 = $90
$90 + $11 = $101

2) they have 150 books altogether.

[tianzhu]

Cher2101:

2). Ben had twice as many books as Eve. If Ben gave Eve 20 books, Ben will have 10 more books than Eve. How many books do they have altogether?

Hi

Good Morning.

As usual, I've drawn more MD than necessary to show the flow of events.Once a student understands the logic, he/she may consolidate the steps.

Hope this helps.

Best wishes

http://farm8.staticflickr.com/7096/7161777140_e26d1d4f2f_z.jpg\">

[peapot]

Hi what method to use for this q?


Darren has some 10cent coins, 20cent coins and 50 cent coins in his pocket that add up to $2. He has exactly 9 coins. How many 20 cent coins does he have?

I found 2 answers. either 3 twenty cent coins or 7 twenty cent coin. Which should be correct?

[peapot]

if i use guess and check method it will be 7 twenty cent coin.