Tutor MathsGuru: Ask me for your burning Maths questions!

[Vanilla Cake]

starlight1968sg:

(2) Look at the pattern below:

Position Number
1st 1
2nd 2
3rd 3
4th 2
5th 3
6th 4
7th 3
8th 4
9th 5
10th 4
11th 5
12th 6
(a) At what position does the number 12 first appear?
(b) What is the sum of the first 32 numbers?

Hi starlight1968sg,
Your 2nd question is a 5-mark question from http://www.orlesson.org/orp/09Ma/2009-Math-SA1-StNic.pdf.
Pls refer to http://psle2010a.blogspot.com/2010/04/challenging-p5-2009-sa1-p2-chij-q16.html while waiting for http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6311 solution.

Uncle Observer's solution
1st group -- > 1 , 2 , 3
2nd group -- > 2 , 3 , 4
3rd group -- > 3 , 4 , 5
….
10th group -- > 10 , 11 , 12

10 x 3 = 30 -- > 30th position

a) The number 12 first appears at the 30th position

1, 2, 3, … 10
(1 + 10) x 10 ÷ 2 = 55

2, 3, 4, … 11
(2 + 11) x 10 ÷ 2 = 65

3, 4, 5, .. 12
(3 + 12) x 10 ÷ 2 = 75

55 + 65 + 75 + 11 + 12 = 218

or

3, 4, 5, … 10
(3 + 10) x 8 ÷ 2 = 52

(1 + 2 + 2 + 3 x 52 + 11 + 11 + 12) + (11 + 12) = 218

b) The sum of the first 32 numbers is 218

[Dharma]

starlight1968sg:

Hi mathsguru and others,

I need some help:
How to solve it?

(2) Look at the pattern below:
Position Number
1st 1
2nd 2
3rd 3
4th 2
5th 3
6th 4
7th 3
8th 4
9th 5
10th 4
11th 5
12th 6
(a) At what position does the number 12 first appear?
(b) What is the sum of the first 32 numbers?

(ans: (a) 30th, (b) 218)

For (a), do we simply write from position 12th till position 30th ie when we first see the number 12?

For (b), the calculations is too lengthy. Is there a method or a pattern one can recognise to simplify the calculation?

MTIA.

http://www.postimage.org/image.php?v=Pq4SUgi

[Daddy]

Hi mathsguru and others,


I have one difficult question. Pls help thanks. :?

1. IF Vaness gave 12 badges to Jay, both of them would have the same number of badges. If Jay gave 24 badges to Vaness, Vaness would have 5 times as many badges as Jay. How many badges did Vaness have?

Thanks alot
Daddy

[Guan Hui]

jay +12 = vaness -12

1u:1u
so when its jay turn to give 24
jay amount become
1u-36(the 12 that was given by vaness must give back)
vaness amount become
1u+36

1u-36:1u+36
1:5
5 times of jay = 1 times of vaness
5 (1u-36)=5u-(5x36)=1u+36
4u=6x36
1u=54

So vaness have 1u+12 so… 66badges

[Jolyn]

Hi Maths Guru


I have a few questions and appreciate if you could help:

1. There are 38 red beans and 3 times as many blue beans in a box. How many blue beans are there in 4 such boxes?

2. The florist sold 4 times as many roses as tulips on Valentine’s Day. If she sold 260 roses and day, how many roses did the florist sell?

Thank you very much…

[Daddy]

Thanks Guan Hui,


Any model for this question, I am confusing. Thanks…

[Maths Monster]

delete

[Maths Monster]

delete

[Daddy]

Hi mathsguru and others,


Thousand thanks to all that had answered my questions.

Another question:

1. The movie tickets sold on Thursday were 2/3 of the tickets sold on Friday. The tickets sold on Friday were 3/5 of the tickets sold on Satursday. If there were 380 movies tickets sold altogether. How many more tickets were sold on Satursday than on Thursday. :oops:

Thanksss.

[Vanilla Cake]

Daddy:

The movie tickets sold on Thursday were 2/3 of the tickets sold on Friday. The tickets sold on Friday were 3/5 of the tickets sold on Saturday. If there were 380 movies tickets sold altogether. How many more tickets were sold on Saturday than on Thursday.

T: [][]

F: [][][]
S: [][][][][]

Total = 10 units = 380
Difference between Saturday and Thursday = (5-2) units = 3 units = 380/10x3=114
There were 114 more tickets sold on Saturday than on Thursday.

Hope this helps while waiting for http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6311 model solution.