Tutor MathsGuru: Ask me for your burning Maths questions!

[MathIzzzFun]

Herbie:

Thanks mathizzfun


I hv another qn

Given tat x=5 *10^4 and y=6*10^-3

FIND 1/X +2Y
thanks

Hi

x = 5 *10^4
1/x = 1/(5 *10^4) = 0.2 * 10^-4 = 2 * 10^-5
2y = 12 *10^-3 = 1200 * 10^-5
1/x + 2y = 2 * 10^-5 + 1200 * 10^-5 = 1202 * 10^-5 = 1.202 x 10^-2

cheers.

[ongmt]

Jason, Edward and Sam had total $837. Jason had the least amont of money. Ratio of Edward money to Sam money was 4:3 at first. Jason and edward spent 1/3 of their money. Given that the 3 boys had $648 left, how much did Jason have at first? :?


Plse help. Thks

[josephgiri]

ongmt:

Jason, Edward and Sam had total $837. Jason had the least amont of money. Ratio of Edward money to Sam money was 4:3 at first. Jason and edward spent 1/3 of their money. Given that the 3 boys had $648 left, how much did Jason have at first? :?


Plse help. Thks

==========
Amt spent by J and E -> $837 - $648 = $189
Initial total of J and E -> $189 x 3 = $567
Initial amount of S -> $837 - $567 = $270

At first, E:S -> 4:3
3u -> $270
1u -> $90
4u -> $360

At first, J -> $567 - $360 = $207
==========

Cheers

[Herbie]

I hv two qn


1. 5/6-2x + 2x-7/x^2-9

2. X^2-4xy+4y^2 =0, find 2x/y

Thanks

[MathIzzzFun]

Herbie:

I hv two qn


1. 5/6-2x + 2x-7/x^2-9

2. X^2-4xy+4y^2 =0, find 2x/y

Thanks

Hi

I believe you have omitted some brackets in the question 1, I have re-write it below - hope it is correct.

http://i50.tinypic.com/14ebdhe.png\">

cheers.

[Herbie]

Thanks!


Can assist on the following qns?

Factorise a(b^2-c^2)-bc(b-c)
Wat do we look out for when doing such qn?

Factorise 4a^2-b^2a-b completely.

Factorise 8/25a^2 -32b^2.
Do u hv any tips in solving qn?

[Herbie]

Deleted

[MathIzzzFun]

Herbie:

Thanks!


Can assist on the following qns?

Factorise a(b^2-c^2)-bc(b-c)
Wat do we look out for when doing such qn?

Factorise 4a^2-b^2a-b completely.

Factorise 8/25a^2 -32b^2.
Do u hv any tips in solving qn?

Hi

the questions are practices for factorisation of
(a+b)(a-b) = a^2-b^2

you may want to try it - factorise a^2-b^2 into (a+b)(a-b) and then look for the common factors, taking note that 4a^2-b^2 can be factorised into (2a+b)(2a-b) ie 4a^2 = (2a)^2.

cheers.

[ongmt]

1) At a party, there were some ballons, 25 ballon burst & 10% of remaining ballons fly away. If only 60% of the ballons were left, how many ballons were there at first?


2) Pkt A, B and C each contained some cement. 1/3 of cement was transferred from Pkt A to B. Then 1/3 of the cement transfer from Pkt B to C. Finally, 1/3 of cement transferred from Pkt C to A. In the end, there were 12kg of cement in each pkt. Whar was the mass of cement in Pkt B at first?

3) A fan club had 150 member last yr. This yr, the no of male member reduced by 20% and number of female member increas by 20%. As a result, there are now as man male member as female members. How many memebers does the club have this year?

Plse help :udaman:

[josephgiri]

ongmt:

2) Pkt A, B and C each contained some cement. 1/3 of cement was transferred from Pkt A to B. Then 1/3 of the cement transfer from Pkt B to C. Finally, 1/3 of cement transferred from Pkt C to A. In the end, there were 12kg of cement in each pkt. Whar was the mass of cement in Pkt B at first?

This is a 'constant total' or 'internal transfer' type of qn.

Working backward

At the end,
A:B:C = 12:12:12

1/3 from C to A,
2 units left in C
1 unit -> 6 kg
A:B:C = 6:12:18

1/3 from B to C,
2 units left in B
1 unit -> 6 kg
A:B:C= 6:18:12

1/3 from A to B,
2 units left in A
1 unit -> 3 kg
A:B:C=9:15:12

Pkt B had 15 kg of cement initially.