Tutor MathsGuru: Ask me for your burning Maths questions!

[Dharma]

abc_parent:

Q3) A set of dictionaries which fitted exactly 4 shelves, each 2.05m long, was replaced by a new set. Every 7 old dictionaries was replaced by 4 new ones, each 5 cm thick. If the new set of dictionaries also fitted the 4 shelves exactly, what was the difference in the number of books between the two sets?


Answer: 120 dictionaries

Total thickness of dictionaries = 4 x 205cm = 820cm

Each shelf will have 205cm/5cm = 41 new dictionaries

No. old dictionaries that were replaced by the new set per row = (41/4) x 7 = 287/4 = 71.75

Only 71 old dictionaries fit into each row of the shelf.
Total number of old dictionaries = 4 x 71 = 284
Total number of new dictionaries = 4 x 41 = 164

Difference in the number of dictionaries = 284 – 164 = 120

(You cannot tear off a portion of a dictionary to force it into a shelf !!!)

[wkong]

Hi,


Thanks for solving thoses previous questions I have post. I have another one that need help.

A shopkeeper has 415 pencils and notebooks. After selling 1/3 of the pencils, he bought 65 notebooks. The ratio of the pencil to the notebook is 6:7.

Question A: How many notebooks did he have at first?
Question B: How many pencils did he have in the end?

[Vanilla Cake]

wkong:

Hi,


Thanks for solving thoses previous questions I have post. I have another one that need help.

A shopkeeper has 415 pencils and notebooks. After selling 1/3 of the pencils, he bought 65 notebooks. The ratio of the pencil to the notebook is 6:7.

Question A: How many notebooks did he have at first?
Question B: How many pencils did he have in the end?

After
P : N
6u : 7u

Before
P : N
9u : 7u-65

9u+7u-65 = 415
16u = 480
u = 30

Notebook (before): 7u-65 = 7(30)-65 = 145
(a) At first, the shopkeeper had 145 notebooks.

Pencil (after): 6u = 6x30 = 180
(b) In the end, the shopkeeper had 180 pencils.

[ruyu]

a question that appeared from my exam i am remembering this with my best ability!


Names differ


Tom had $200 more than Harry. In the afternoon, Tom gave some money to Harry. The ratio to the amount he had left to the amount he gave away is 2:3. In the evening, Harry gave some money to Tom. The ratio of the amount he had left to the amount he gay away is 3:1. In the end, Harry had $200 more than Tom. How much did Tom have at first?

one more question , can you please check if there is a mistake my friends and i could not even get the answer! UNDOABLE!

Tom and Harry bought some cartons of soya bean drink and herbal tea. Tom bought 3/8 of the cartons. Both of them bought 48 more cartons of soya bean drink than herbal tea. Harry bought 2/5 of the soya bean drink and 1/2 of the herbal tea. How many cartons did Tom buy?

Thanks for your help!

[ruyu]

ruyu:

Cheerfuldad:

Hi all,


P5 question:
At a party, Mrs Ong gave each pupil 5 nuggets and had 30 nuggets left. If she gave each pupil 6 nuggets, she would have 4 nuggets left. How many nuggets did Mrs Ong prepare for the party? :?

TIA

For the 5 nuggets start from 30 and continue by adding 5 nuggets

30,35,40,50,55

For the 6 nuggets start from 4 and continue by adding 6 nuggets

4,10,16,22,28,34,40,46

Than the common number between this two is 40 thus the answer is 40

Hope it helped


Best regard,

Ruyu

i am sorry :oops: :oops: :oops: was quite sleepy did not notice

[verykiasu2010]

ruyu:

ruyu:

[quote=\"Cheerfuldad\"]Hi all,


P5 question:
At a party, Mrs Ong gave each pupil 5 nuggets and had 30 nuggets left. If she gave each pupil 6 nuggets, she would have 4 nuggets left. How many nuggets did Mrs Ong prepare for the party? :?

TIA

For the 5 nuggets start from 30 and continue by adding 5 nuggets

30,35,40,50,55

For the 6 nuggets start from 4 and continue by adding 6 nuggets

4,10,16,22,28,34,40,46

Than the common number between this two is 40 thus the answer is 40

Hope it helped


Best regard,

Ruyu

i am sorry :oops: :oops: :oops: was quite sleepy did not notice [/quote]
30 nuggets - 4 nuggets = 26 pupils

original number of nuggets = 26 x 5 + 30 = 160

or : 26 x 6 + 4 = 160

[ruyu]

a question that appeared from my exam i am remembering this with my best ability!


Names differ


Tom had $200 more than Harry. In the afternoon, Tom gave some money to Harry. The ratio to the amount he had left to the amount he gave away is 2:3. In the evening, Harry gave some money to Tom. The ratio of the amount he had left to the amount he gay away is 3:1. In the end, Harry had $200 more than Tom. How much did Tom have at first?

one more question , can you please check if there is a mistake my friends and i could not even get the answer! UNDOABLE!

Tom and Harry bought some cartons of soya bean drink and herbal tea. Tom bought 3/8 of the cartons. Both of them bought 48 more cartons of soya bean drink than herbal tea. Harry bought 2/5 of the soya bean drink and 1/2 of the herbal tea. How many cartons did Tom buy?

Thanks for your help!

[Vanilla Cake]

ruyu:

Tom had $200 more than Harry. In the afternoon, Tom gave some money to Harry. The ratio to the amount he had left to the amount he gave away is 2:3. In the evening, Harry gave some money to Tom. The ratio of the amount he had left to the amount he gay away is 3:1. In the end, Harry had $200 more than Tom. How much did Tom have at first?

Before
T: u+$200
H: u

Tom
Left : Gave
2 : 3

T-> 2/5 of u + 2/5 of $200 = 2/5 of u + $80
H-> u + 3/5 of u + 3/5 of $200 = 8/5 of u + $120

Harry
Left : Gave
3 :1

H->3/4 of (8/5 of u + $120) = 6/5 of u + $90
T-> 2/5 of u + $80 + 1/4 x (8/5 of u + $120) = 4/5 of u + $110

In the end, Harry had $200 more than Tom.

4/5 of u + $110 + $200 = 6/5 of u + $90
2/5 of u = $220
u = $550

$(550+200) = $750
At first, Tom had $750.

[ruyu]

Vanilla Cake:

ruyu:

Tom had $200 more than Harry. In the afternoon, Tom gave some money to Harry. The ratio to the amount he had left to the amount he gave away is 2:3. In the evening, Harry gave some money to Tom. The ratio of the amount he had left to the amount he gay away is 3:1. In the end, Harry had $200 more than Tom. How much did Tom have at first?

Before
T: u+$200
H: u

Tom
Left : Gave
2 : 3

T-> 2/5 of u + 2/5 of $200 = 2/5 of u + $80
H-> u + 3/5 of u + 3/5 of $200 = 8/5 of u + $120

Harry
Left : Gave
3 :1

H->3/4 of (8/5 of u + $120) = 6/5 of u + $90
T-> 2/5 of u + $80 + 1/4 x (8/5 of u + $120) = 4/5 of u + $110

In the end, Harry had $200 more than Tom.

4/5 of u + $110 + $200 = 6/5 of u + $90
2/5 of u = $220
u = $550

$(550+200) = $750
At first, Tom had $750.

my answer $350 but can get methord marks

[ruyu]

Vanilla Cake:

ruyu:

Tom had $200 more than Harry. In the afternoon, Tom gave some money to Harry. The ratio to the amount he had left to the amount he gave away is 2:3. In the evening, Harry gave some money to Tom. The ratio of the amount he had left to the amount he gay away is 3:1. In the end, Harry had $200 more than Tom. How much did Tom have at first?

Before
T: u+$200
H: u

Tom
Left : Gave
2 : 3

T-> 2/5 of u + 2/5 of $200 = 2/5 of u + $80
H-> u + 3/5 of u + 3/5 of $200 = 8/5 of u + $120

Harry
Left : Gave
3 :1

H->3/4 of (8/5 of u + $120) = 6/5 of u + $90
T-> 2/5 of u + $80 + 1/4 x (8/5 of u + $120) = 4/5 of u + $110

In the end, Harry had $200 more than Tom.

4/5 of u + $110 + $200 = 6/5 of u + $90
2/5 of u = $220
u = $550

$(550+200) = $750
At first, Tom had $750.

is the other question doable?