Q&A - P5 Math

[Winx5015]

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[tianzhu]

Hi


a+b+d+f ---------360 (sum of interior angles in a 4 sided figure)

c+e+g -------180 (triangle)

a+b+c+d+e+f+g ------ 540

Divide the 6 sided figure (blue) into 4 triangles.

u+v+w+x+y+z --------4*180 -------720

Best wishes

[Essential]

Hi, need some help to solve this question.

The ration of Ben’s cards to Benny’s cards was 3:4 After Ben bought another 9 cards and Benny lost 18 cards , the ration became 3:2. Find the total number of cards Ben and Benny had at first.

[Essential]

Mathizzfun, could you help me with this question?

Rosie, sandy and Tabby shared a box of cards. Rosie took 1/5 of th total number of cards and another 12 cards. Sandy took 50% of the remaining cards in the box another 13 cards . Tabby took the last 27 cards in the box. How many cards were there in the box at first?

[MathIzzzFun]

Essential:

Mathizzfun, could you help me with this question?

Rosie, sandy and Tabby shared a box of cards. Rosie took 1/5 of th total number of cards and another 12 cards. Sandy took 50% of the remaining cards in the box another 13 cards . Tabby took the last 27 cards in the box. How many cards were there in the box at first?

Hi

work backwards..

13+27 = 40 = 50% of remaining cards ,
remaining cards after Rosie took = 2 x 40 = 80
80 + 12 = 4/5 of total number of cards =92
Total number of cards in the box = 5/4 x 92 = 115

cheers.

[MathIzzzFun]

Essential:

Hi, need some help to solve this question.

The ration of Ben's cards to Benny's cards was 3:4 After Ben bought another 9 cards and Benny lost 18 cards , the ration became 3:2. Find the total number of cards Ben and Benny had at first.

Hi

At first, Ben : Benny = 3u : 4u

After Ben bought another 9 cards and Benny lost 18,
Ben : Benny = 3u + 9 : 4u - 18 = 3 : 2

Cross multiply-
2(3u+9) = 3(4u-18)
6u + 18 = 12u - 54
6u = 72, 1u = 12

3u = 36, 4u = 48. Ben had 36 cards and Benny had 48 cards at first.

cheers.

[Essential]

Hi MathIzzfun, thank you so much for your replied.

[MathIzzzFun]

Essential:

Hi MathIzzfun, thank you so much for your replied.

u r welcome

cheers.

[Superbugs]

MGS SA2 2011


Q26
Jerry had some beads. He can divide them equally into 2, 5 or 7 groups. What was the max. number of beads that he had if he had less than 250 beads?

Q29
The figure below has a perimeter of 36cm. It is made up of 9 identical triangles. What is the increase in the perimeter of the figure when a row of triangles is added to the base?
Regret that I do not know how to incorporate the figure here.
My solution: 36/9= 4cm
Increase triangles = 9 - 4base, 2 sides
Hence 6x4=24cm
However answer is only 12cm?

Pls help!

[tianzhu]

Superbugs:

MGS SA2 2011

Q26
Jerry had some beads. He can divide them equally into 2, 5 or 7 groups. What was the max. number of beads that he had if he had less than 250 beads?

Hi

For Q26, find the common multiple of 2, 5 and 7 closest to 250, the answer is 210.

A common method used in primary maths is “Systematic Listing”

A faster way to find the lowest multiple of 70 and multiply by 3.

Best wishes