Q&A - P5 Math

[happyheart]

Can anyone help to solve? This sort of question carries 2 marks . How can We best present the solution? Thank you.


Q: Lawrence has some pens.
When he packs them into bundles of 5 pens in each bundle, he will have 3 extra pens.
When he packs them into bundle of 9 pens in each bundle, he will need another 8 pens. How many pens are there?

[highanxiety]

What message to decode?

[mummyv]

happyheart:

Can anyone help to solve? This sort of question carries 2 marks . How can We best present the solution? Thank you.


Q: Lawrence has some pens.
When he packs them into bundles of 5 pens in each bundle, he will have 3 extra pens.
When he packs them into bundle of 9 pens in each bundle, he will need another 8 pens. How many pens are there?

hi

am not sure if this is the easiest method for 2 marks! anyone got an easier way?

Difference is 8+3=11 cos compare (multiple of 9 Less8) & (multiple of 5 R3)
List multiples of 9 : 9,18,27,36
Use guess and check to find multiple of 5
18-11=7 wrong
27-11=16 wrong
36-11=25 correct
Work backwards
25 = 5x5
5x5+3=28 (multiple of 5 R3)
28+8=36 (multiple of 9 Less8)
Ans: 28

[Nebbermind]

mummyv:

happyheart:

Can anyone help to solve? This sort of question carries 2 marks . How can We best present the solution? Thank you.


Q: Lawrence has some pens.
When he packs them into bundles of 5 pens in each bundle, he will have 3 extra pens.
When he packs them into bundle of 9 pens in each bundle, he will need another 8 pens. How many pens are there?

hi

am not sure if this is the easiest method for 2 marks! anyone got an easier way?

Difference is 8+3=11 cos compare (multiple of 9 R8) & (multiple of 5 R3)
List multiples of 9 : 9,18,27,36
Use guess and check to find multiple of 5
18-11=7 wrong
27-11=16 wrong
36-11=25 correct
Work backwards
25 = 5x5
5x5+3=28 (multiple of 5 R3)
28+8=36 (multiple of 9 R8)
Ans: 28

Not able to provide the solution but when bundled in 9s, the remainder is 1 and not 8.

[mummyv]

Nebbermind:

Not able to provide the solution but when bundled in 9s, the remainder is 1 and not 8.

Hi
I used the wrong term not R8 but Less 8 according to the question. To avoid confusion will edit my earlier post.

[Mychildren]

I worked it in this way:


_ x5 + 3 = Ans
10 + 3 = 13
15 + 3 = 18
25 + 3 = 28;

_ x 9 - 8 = Ans
18 - 8 = 10
27 - 8 = 21
36 - 8 = 28

So 28 is the answer.

[mummyv]

Mychildren:

I worked it in this way:


_ x5 + 3 = Ans
10 + 3 = 13
15 + 3 = 18
25 + 3 = 28;

_ x 9 - 8 = Ans
18 - 8 = 10
27 - 8 = 21
36 - 8 = 28

So 28 is the answer.

This way is so much easier thanks sometimes i just make it too complicated

[happyheart]

Thank you, the method looks simplified enough:)

[keinic]

Hi


Appreciate if someone could help with the following question:

Mrs Tan bought 4 times as many toy guns as teddy bears. She spent $1750 altogether. A toy gun costs $10 less than a teddy bear. The total cost of toy guns was $490 more than the total cost of teddy bears.

a) How much did Mrs Tan spend on the teddy bears?
b) How much did one teddy bear cost?

TIA.

[tianzhu]

keinic:

Hi


Appreciate if someone could help with the following question:

Mrs Tan bought 4 times as many toy guns as teddy bears. She spent $1750 altogether. A toy gun costs $10 less than a teddy bear. The total cost of toy guns was $490 more than the total cost of teddy bears.

a) How much did Mrs Tan spend on the teddy bears?
b) How much did one teddy bear cost?

TIA.

Hi

One neat way is to use MD.

Amount spent on teddy bears ------ (1750-490)/2 ----- 630
Amount spent on toy guns ------- 630 + 490 ----- 1120

Toy guns ------ 4 units
Teddy bears ------- 1 unit

1 unit ------- 1120/4 ----- 280

630 - 280 ------- 350

The cost of 350 is due to teddy bear costing $10 more.

Number of teddy bears ------ 350/10 ------- 35

Cost of 1 teddy bear ----- 630/35 ----- 18

Best wishes