Q&A - P5 Math

[tianzhu]

YumYum:

Hi, need help with this question:


1) Mr goh sold an equal number of apples and oranges. He sold the apples at $5 and $3 and the oranges at 7 for $4. At the end of the day, he collected $8 more from the sale of apples than the sale of oranges. How much money did he receive in total.

2) Aaron had a total of 336 Singapore and Malaysia stamps. He gave away 4/7 of the Singapore stamps and bought another 24 Malaysia stamps. As a result, the number of Malaysia stamps he had was 2/3 the number of singapore stamps left. How many more Singapore stamps than Malaysia stamps had he at first?

Thanks

Hi

For Q1,a common multiple of 5 and 7 is 35.

7 groups of apples ------- 21

5 groups of oranges ------- 20

Difference ------- 1

He collected $8 more from the sale of apples than the sale of oranges.

(21+20)*8 ------- 328

For Q2, a neat way is to use MD.

Draw 7 boxes to show Singapore stamps.

He gave away 4 boxes, this leaves remainder of 3 boxes.

Draw a bar of length of 2 boxes less 24 to show Malaysian stamps in the end.

9 units ------- 336+ 24

1 unit ------ 40

Singapore stamps@first ------- 280

Malaysian stamps@first ------- 56

Please carry on from here.

Best wishes

[Udon]

Please help to explain the answer provided for this Question...Thanks.


Q1. What is the maximum number of wooden blocks measuring 0.03m by 0.02m by 0.06m that can be cut from a big block of wood measuring 12 cm by 11 cm by 15 cm？

Given answer:-

0.03m x 100 = 3 cm
0.02m x 100 = 2 cm
0.06m x 100 = 6cm

12 divided by 6 = 2
why 12/6, why not the \"length / length and the breadth / breadth and the height / height manner? :?:

11 divided by 2 = 5 R 1
15 divided by 3 = 5

2 x 5 x 5 = 50
The maximum number of wooden blocks that can be cut is 50.


Best Regards
Udon

[MathIzzzFun]

Udon:

Please help to explain the answer provided for this Question...Thanks.


Q1. What is the maximum number of wooden blocks measuring 0.03m by 0.02m by 0.06m that can be cut from a big block of wood measuring 12 cm by 11 cm by 15 cm？

Given answer:-

0.03m x 100 = 3 cm
0.02m x 100 = 2 cm
0.06m x 100 = 6cm

12 divided by 6 = 2
why 12/6, why not the \"length / length and the breadth / breadth and the height / height manner? :?:

11 divided by 2 = 5 R 1
15 divided by 3 = 5

2 x 5 x 5 = 50
The maximum number of wooden blocks that can be cut is 50.


Best Regards
Udon

Maximum number of blocks that can be cut is 54

http://i47.tinypic.com/1251jeq.png\">

cheers.

[imacsg]

Yazid and his class raced one another across a field. Midway through the race, 1/5 of Yazid’s classmates was running in front of him and 7/9 of the total number of pupils in the class was running behind him. What was the total number of pupils in the class including Yazid?


Can anyone solve the above question? Thanks

[tianzhu]

imacsg:

Yazid and his class raced one another across a field. Midway through the race, 1/5 of Yazid's classmates was running in front of him and 7/9 of the total number of pupils in the class was running behind him. What was the total number of pupils in the class including Yazid?


Can anyone solve the above question? Thanks

Hi

Is this a MCQ question or open ended question?

The answer is 36.

Best wishes

[MathIzzzFun]

imacsg:

Yazid and his class raced one another across a field. Midway through the race, 1/5 of Yazid's classmates was running in front of him and 7/9 of the total number of pupils in the class was running behind him. What was the total number of pupils in the class including Yazid?


Can anyone solve the above question? Thanks

Total number in class --> 9u
Pupils in front --> 2u-1, class mates --> 9u-1
so, 2u -1 : 9u-1 = 1 : 5
cross multiply/equalize:
10u-5 = 9u-1
1u--> 4
total number in class --> 36
cheers.

[imacsg]

MathIzzzFun,

Thanks, I also have 45 as the ans.
But the ans is 36, I think the ans is wrong.

[MathIzzzFun]

imacsg:

MathIzzzFun,

Thanks, I also have 45 as the ans.
But the ans is 36, I think the ans is wrong.

oops..I read the question as 1/5 of class in front and 7/9 of class behind --> should be 1/5 of classmates (ie total number -1) in front and 7/9 class behind

Total number in class --> 9u
Pupils in front --> 2u-1, class mates --> 9u-1
so, 2u -1 : 9u-1 = 1 : 5
cross multiply/equalize:
10u-5 = 9u-1
1u--> 4
total number in class --> 36

cheers.

[imacsg]

Hi MathIzzzFun,

You are sharp, I also did not notice that. Thanks

[MathIzzzFun]

imacsg:

Hi MathIzzzFun,

You are shape, I also did not notice that. Thanks

solution using MD..


http://i48.tinypic.com/33dfplz.png\">

cheers.