Tutor MathsGuru: Ask me for your burning Maths questions!

[Daddy]

Hi,


Need help!

1. Chloe has a box of beads. 2/7 of the beads are white and the rest are blue and orange beads. The ratio of the number of white beads to the number of blue beads is 6:5. find the ratio of the number of blue beads to orange beads. Give your answer in the simplest form.

Thanks…
Daddy.

[iFruit]

Daddy:

Hi,


Need help!

1. Chloe has a box of beads. 2/7 of the beads are white and the rest are blue and orange beads. The ratio of the number of white beads to the number of blue beads is 6:5. find the ratio of the number of blue beads to orange beads. Give your answer in the simplest form.

Thanks..
Daddy.

2/7 beads are white. So White: (blue+orange) = 2:5 = 6:15

white: Blue = 6:5

Observing the above two ratios we deduce

whilte:blue:orange = 6:5:10

So blue:orange = 5:10 = 1:2

[iFruit]

noob:

Need solution for following question, please help tks


Alice, Betty and Cecilia shared the cost of a present. Alice paid 1/3 of the total amount of money paid by Betty and Cecilia. Betty paid 1/8 of the amount of money paid by Alice and Cecilia. Alice paid $60 less than Cecilia.
(a) How much did Betty pay?
(b) What was the cost of the present?

Is there a typo in the question? Perhaps \"Alice paid $70 less than Cecilia\"?

Below is working assuming \"Alice paid $70 less than Cecilia\". With $60, it is the same working but we end up with all fractions

Alice = A, Betty = B and Cecilia = C.

A = 1/3 (B +C) ----> 3A = B+C ---------(1)
B = 1/8 (A+C) -----> 8B = A+C ---------(2)
C = A + 70---(3)

Substituting (3) in (1) and (2) we get

3A = B+A+70 -----> 2A = B+70
8B = A +A +70----> 8B = 2A +70

From the above two we get, 8B = B+70+70 or B = 20

The A = 45, C = 115, Total = 115+45+20 = 180

HTH

[noob]

iFruit:

noob:

Need solution for following question, please help tks


Alice, Betty and Cecilia shared the cost of a present. Alice paid 1/3 of the total amount of money paid by Betty and Cecilia. Betty paid 1/8 of the amount of money paid by Alice and Cecilia. Alice paid $60 less than Cecilia.
(a) How much did Betty pay?
(b) What was the cost of the present?

Is there a typo in the question? Perhaps \"Alice paid $70 less than Cecilia\"?

Below is working assuming \"Alice paid $70 less than Cecilia\". With $60, it is the same working but we end up with all fractions

Alice = A, Betty = B and Cecilia = C.

A = 1/3 (B +C) ----> 3A = B+C ---------(1)
B = 1/8 (A+C) -----> 8B = A+C ---------(2)
C = A + 70---(3)

Substituting (3) in (1) and (2) we get

3A = B+A+70 -----> 2A = B+70
8B = A +A +70----> 8B = 2A +70

From the above two we get, 8B = B+70+70 or B = 20

The A = 45, C = 115, Total = 115+45+20 = 180

HTH

No typo error, answer (a) $12 (b) $108

[Daddy]

Hi Ifruit,

[quote]2/7 beads are white. So White: (blue+orange) = 2:5 = 6:15

white: Blue = 6:5

Observing the above two ratios we deduce

whilte:blue:orange = 6:5:10
[/quote]Compare set of ratio of White & Blue to White , blue & orange.

first:
White : blue+Orange
....... 2 : 5

given:
White : Blue
___ 6 :5

X3 =>White : blue+Orange
........ 6 : 15
seperate blue & orange
White : Blue : Orange
___ 6 : 5 : 10

reduce ratio of Blue & Orange = 1:2

Thanks ..

[Daddy]

Hi,


Another Question to ask..Thanks

1. Evaluate the following series:
(2010-2009+2008) + (2007-2006+2005) +...+(1020-1019+1018).

:? What question is this? :!:
Thanks

[x6michelle9x]

Hi, I would appreciate if someone can help to solve this problem without using algebra, thanks in advance!


The average cost of a few books was $8. After a book which costs $32 was added, the average cost becomes $12. How many books are there now?

[iFruit]

noob:

iFruit:

[quote=\"noob\"]Need solution for following question, please help tks


Alice, Betty and Cecilia shared the cost of a present. Alice paid 1/3 of the total amount of money paid by Betty and Cecilia. Betty paid 1/8 of the amount of money paid by Alice and Cecilia. Alice paid $60 less than Cecilia.
(a) How much did Betty pay?
(b) What was the cost of the present?

Is there a typo in the question? Perhaps \"Alice paid $70 less than Cecilia\"?

HTH

No typo error, answer (a) $12 (b) $108[/quote]
There is an error in the problem. If the answers are right, then it should be \"Alice paid 1/5 of the total amount of money paid by Betty and Cecilia\"

Alice = A, Betty = B and Cecilia = C.

A = 1/5 (B +C) ----> 5A = B+C ---------(1)
B = 1/8 (A+C) -----> 8B = A+C ---------(2)
C = A + 60---(3)

Substituting (3) in (1) and (2) we get

5A = B+A+60 -----> 4A = B+60
8B = A +A +60----> 8B = 2A +60

From the above two we get, 16B = B+60+120 or B = 12

The A = 18, C = 78, Total = 78+18+12 = 108

[iFruit]

Daddy:

Hi,


Another Question to ask..Thanks

1. Evaluate the following series:
(2010-2009+2008) + (2007-2006+2005) +...+(1020-1019+1018).

:? What question is this? :!:
Thanks

Need to know a couple of formulas for this type of problems..

Each term in bracket reduces to (smallest number +1), with difference in terms being three...so the sequence is like

1019, 1022, 1025.....2009 (from right to left) with a common diff of 3

So number of terms = (last term - first term)/diff + 1 = (2009 - 1019)/3 + 1 = 331

Sum of terms = (last term + first term)(num of terms)/2 = (1019 + 2009)x331/2 = 3028 x 331/2 = 1514 x 331 = 501134

[kancheongmum]

x6michelle9x:

Hi, I would appreciate if someone can help to solve this problem without using algebra, thanks in advance!


The average cost of a few books was $8. After a book which costs $32 was added, the average cost becomes $12. How many books are there now?

Hi x6michelle9x

$32 - $12 = $20 (we have to minus out the book that was added)

$20 is the amount that contribute to the increased of the average cost of a few books

$12 - $8 = $4

$20/$4 = 5 books

No. of books now --- 5+1 = 6 books (answer)

Check:
$8 x 5 = $40
$40+$32 = $72
$72/6 = $12