Tutor MathsGuru: Ask me for your burning Maths questions!

[leesf]

Hi Mathsguru,


I have a question.

A & B share some beads. If A gives B 1/3 of his share, B would have 70 beads more than A. If A gives B 1/5 of his share, B would ahve 10 beads more than A. How many beads do A have at first?

Thanks

[fanren]

Hi

i have a qn hope someone can help.

Bobby places 12 cards on a table. Each card is either red or black in colour. If the fraction of black cards is 7/12, what is the smallest number of additionals cards that Bobby needs to put on the table so that the fraction of black cards becomes 5/8 ?

thanks in advance!

[tianzhu]

Hi

Hope this helps.
http://farm5.static.flickr.com/4049/4381269779_fb81993e83_o.jpg\">

Best wishes

[stuckinratio]

Hi maths guru,


have this q

The no of cakes was twice the no of cream puffs. After 90 cakes and 42 cream puffs were sold, the ratio of the no of cakes left to the no of cream puffs was 2:5. How many cakes and cream puffs were in the shop at first?

TIA

[stuckinratio]

Hi maths guru,


have this q

The no of cakes was twice the no of cream puffs. After 90 cakes and 42 cream puffs were sold, the ratio of the no of cakes left to the no of cream puffs was 2:5. How many cakes and cream puffs were in the shop at first?

TIA

(oops- new to this and posted a new thread instead -sorrieee)

[Dharma]

leesf:

Hi Mathsguru,


I have a question.

A & B share some beads. If A gives B 1/3 of his share, B would have 70 beads more than A. If A gives B 1/5 of his share, B would ahve 10 beads more than A. How many beads do A have at first?

Thanks

If A gives B 1/3 of his share
At last
A : 15units – 5 unit = 10 units
B : 10 units + 70

At first
A : 15 units
B : 10 units + 70 – 5 unit = 5 units + 70

If A gives B 1/5 of his share
At last
A = 15units – 3 units = 12 units
B = 12 units + 10

At first
A : 15 units = 225
B = 12 units + 10 – 3 units = 9 units + 10

The no. of beads that A or B had at first must be the same for both the conditions.

5 units + 70 = 9 units + 10
4 units = 60
1 unit = 15

No. of beads that A had at first = 15 x 15 = 225

[cafelatte]

Need to know the step-by-step thinking procedure for solution this question :


When one of the following numbers is excluded, the sum of the remaining numbers is divisible by 2,3 and 5. What is the number?
29,28,32,45,29,47,17,11?

[Dharma]

cafelatte:

Need to know the step-by-step thinking procedure for solution this question :


When one of the following numbers is excluded, the sum of the remaining numbers is divisible by 2,3 and 5. What is the number?
29,28,32,45,29,47,17,11?

1.\tTo divide by 2 – the ones digit must be an even number
2.\tTo divide by 3 – the sum of digits must be divisible by 3
3.\tTo divide by 5 – the ones digit must be either 0 or 5

Therefore the number must have ones digit that is 0 and the sum of digits must be divisible by 3.

Adding up the ones digits of the 8 numbers given
9 + 8 + 2 + 5 + 9 + 7 + 7 + 1 = 48

In order for the number’s ones digit to be 0, must remove 28 (ones digit is 8 ) so that we can get 0 as the ones digit of the number

Sum = 29 + 32 + 45 + 29 + 47 + 17 + 11 = 210

[cafelatte]

Brilliant ! Thanks Dharma ! Why didn't I think of that ?

[P5G]

cafelatte:

Need to know the step-by-step thinking procedure for solution this question :


When one of the following numbers is excluded, the sum of the remaining numbers is divisible by 2,3 and 5. What is the number?
29,28,32,45,29,47,17,11?

29 + 28 + 32 + 45 + 29 + 47 + 17 + 11 = 238

2 x 3 x 5 = 30

238/30 = 7 r 28 --> remove 28