Q&A - P5 Math

[MathIzzzFun]

concerned1970:

Sry still got few more ques.


1) Sophia bought an equal number of oranges and pears for a party. The oranges were bought at 7 for $2 and the pears were bought at 5 for $3. She paid $33 more for the pears than for the oranges. A) How much did Sophia pay in all? B) How many oranges and pears did she buy altogether?

2) May and Tom had an equal number of sweets. Each day, May ate 12 sweets and Tom ate 6 more than her. When Tom had 24 sweets left, May had 96 sweets
left. How many sweets did each of them have at first?

3) Ray and Tim had the same amount of pocket money. Each day, Ray spent $4 and Tim spent $6. When Tim had $12 left, Ray had 4 times as much money left as Tim. How much was each boy's pocket money at first?

Pls do not use algebra to solve the pb sums. Ty in adv.

Q2.
May will have 6 more sweets than Tom each day.
96 - 24 = 72
72 / 6 = 12 --> May had 96 sweets left after 12 days.
Number of sweets each had at first = 12 x 12 + 96 = 240

Q3 is similar to Q2.
Ray had 4 times as much left as Tim --> Ray had 3 times more than Tim = 3 x $ 12 = $36
Each day, Ray will have $6 - $4 = $2 more than Tim
$36 / $ 2 = 18 days
At first, each boy had 18 x 6 + 12 = $ 120

cheers.

[concerned1970]

MathIzzzFun:

concerned1970:

Need help on several ques! Ty in advance.



3) Find the height of a triangle given that its area is 48cm2 and its base is 12 cm.

Hi

area of triangle = 1/2 x base x height... you can work out the height from here.

cheers.

Tysm for yr help. I know the formula but don't know the exact workings. Pls elaborate.

[MathIzzzFun]

concerned1970:

MathIzzzFun:

[quote=\"concerned1970\"]Need help on several ques! Ty in advance.



3) Find the height of a triangle given that its area is 48cm2 and its base is 12 cm.

Hi

area of triangle = 1/2 x base x height... you can work out the height from here.

cheers.

Tysm for yr help. I know the formula but don't know the exact workings. Pls elaborate.[/quote]48 = 1/2 x 12 x height
height = 48/6 = 8 cm

cheers.

[concerned1970]

48 = 1/2 x 12 x height

height = 48/6 = 8 cm

cheers.[/quote]

Ty for yr help

[concerned1970]

HI. Need help on following ques.


1) Mrs Tan required 3/4 kg of flour to make 96 cookies. If she had only 5/8 of the flour. How many cookies could she make?

2) 1/4 of the pizza was given to David and 2/9 of the remainder was given to Joe. The rest was then distributed equally among 7 boys. What fraction of the pizza did each boy receive?

3) On a bus, there were 32 more females than males. At a particular bus stop, 12 females alighted from the bus and 4 males boarded the bus. There were twice as many females as males in the end.
a) What was the total number of males at the bus stop? b) How many females were there on the bus at first?

4) Gina and Mike had same amount of money. After Gina gave $42 to Mike, Mike had twice as much money as Gina. How much money did Mike have in the end?

[tianzhu]

concerned1970:

2) 1/4 of the pizza was given to David and 2/9 of the remainder was given to Joe. The rest was then distributed equally among 7 boys. What fraction of the pizza did each boy receive?

Hi

Hope this helps.

Best wishes

http://farm8.staticflickr.com/7106/6992109780_f3eabebb85_z.jpg\">

[tianzhu]

concerned1970:

HI. Need help on following ques.

1) Mrs Tan required 3/4 kg of flour to make 96 cookies. If she had only 5/8 of the flour. How many cookies could she make?

Hi

A common multiple of 4 and 8 is 16.

12 units -------- 96
1 unit -------- 8

10 units -------- 80

She could make 80 cookies

Best wishes

[tianzhu]

concerned1970:

3) On a bus, there were 32 more females than males. At a particular bus stop, 12 females alighted from the bus and 4 males boarded the bus. There were twice as many females as males in the end.
a) What was the total number of males at the bus stop? b) How many females were there on the bus at first?

4) Gina and Mike had same amount of money. After Gina gave $42 to Mike, Mike had twice as much money as Gina. How much money did Mike have in the end?

Hi

Q3)

A neat way to use is MD.

In the end

Male passengers ------ 1 unit + 4
Female passengers ------ 1 unit + 20(32-12)

2 units + 8 --------1 unit + 20
1 unit ------12

Total number of female passengers in the bus at first ------ 1 unit + 32 -------44

For (a),we only know 4 male passengers boarded the bus at the particular bus stop.

If the question setter expected students to find out the number of male passengers in the bus after boarding, the answer is 16. (The bus will be at the bus stop before moving off to the next stop)

Q4)

A neat way is using MD.

1 unit ------ 42+42 -------84

Mike ------ 2 units ------ 168

Best wishes

[cimman]

tianzhu:

concerned1970:

2) Calvin had some marbles. He gave 63 of them to Danny and 2/5 of the remainder to Ellen. After that, he found that he still had 1/4 of his marbles left. A) What fraction of his marbles did he give to Danny? B) How many marbles did Calvin have at first?

Hi

You may work with units or MD.

¼ of marbles --------- 3 units

Total marbles -------- 12 units

7 units ------- 63
1 unit ------- 9

He gave to Danny 2/12 or 1/6 of his marbles.

Calvin had 108 (12*9) marbles at first.

Best wishes

I believe the question should be phrased: What fraction of his marbles did he give to Ellen ?

[tianzhu]

cimman:

I believe the question should be phrased: What fraction of his marbles did he give to Ellen ?

Hi

He gave to Danny 63/108 or 7/12 of his marbles.

I'll revise the earlier solution.

Thank you.

Best wishes