Maths questions help

samin101

Can someone help me with this question as it is due tmrw and i have no clue how to attempt it and get the answer.

This one

Hmm..I think ive done that question before

(edited 4 years ago)

😴😴

Find expressions for the chance of picking a red ball from each one of the bags after two blue balls have been taken from one bag and placed into the other.
Remember that the chance of picking a red ball from each of these bags is the same, so equate the expressions to each other.
What you have written down is correct so far, keep going!

Reply 5

samin101

Original post by jamiecjx

So 30/n+2 = n/12

Reply 6

jamiecjx

Original post by samin101

So 30/n+2 = n/12

Remember the probability is

\frac{number\ of\ red\ balls}{number\ of\ red\ and\ blue\ balls}

, you just did

\frac{number\ of\ red\ balls}{number\ of\ blue\ balls}

You should end up with something like this (hidden in spoiler so you can check)

Spoiler

(edited 4 years ago)

Reply 7

samin101

Original post by jamiecjx

Remember the probability is

\frac{number\ of\ red\ balls}{number\ of\ red\ and\ blue\ balls}

, you just did

\frac{number\ of\ red\ balls}{number\ of\ blue\ balls}

So 30/n+32 = n/n+12

Reply 8

samin101

Original post by jamiecjx

Remember the probability is

\frac{number\ of\ red\ balls}{number\ of\ red\ and\ blue\ balls}

, you just did

\frac{number\ of\ red\ balls}{number\ of\ blue\ balls}

You should end up with something like this (hidden in spoiler so you can check)

Spoiler

So what should i do next? Im really bad at maths 😂

Reply 9

jamiecjx

Original post by samin101

So 30/n+32 = n/n+12

Yep now solve for n, start by getting rid of the fractions. Multiply both sides by (n+32) and (n+12)

Something like this should come out of it.

Spoiler

You will end up with a quadratic equation, which has two answers. One of these answers will not make any sense, and will be discarded.

Reply 10

samin101

Original post by jamiecjx

Yep now solve for n, start by getting rid of the fractions. Multiply both sides by (n+32) and (n+12)

Something like this should come out of it.

Spoiler

You will end up with a quadratic equation, which has two answers. One of these answers will not make any sense, and will be discarded.

So n^2+2n-360=0 but then you cannot factorise them

Reply 11

jamiecjx

Original post by samin101

So n^2+2n-360=0 but then you cannot factorise them

You can actually factorise it, but if you can't think of a way, just use the quadratic formula to find the solutions.

Spoiler

Reply 12

samin101

[quote="jamiecjx;88119386"]You can actually factorise it, but if you can't think of a way, just use the quadratic formula to find the solutions.

Spoiler

Thank you so much. You have been such a great help

Reply 13

jamiecjx

Original post by samin101

Thank you so much. You have been such a great help

My pleasure :smile:

Reply 14

samin101

Original post by jamiecjx

My pleasure :smile:

Could you help with this question?

image.jpg523.0KB

Reply 15

jamiecjx

Original post by samin101

Could you help with this question?

So for this question there are a lot of approaches you could do.
ngl, I don't really know what you wrote down here, so Imma just start again.

For convenience, call