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December 07, 2019, 11:57:40 pm

Author Topic: Mathematics Question Thread  (Read 621096 times)  Share 

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fun_jirachi

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Re: Mathematics Question Thread
« Reply #4410 on: October 24, 2019, 09:03:53 pm »
+1
Hey there!

They earn half a cent per member per day, not half a dollar. This means they are correct in multiplying by $0.005 as opposed to the $0.50 that half a dollar would get you.

Hope this helps :)
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Hawraa

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Re: Mathematics Question Thread
« Reply #4411 on: October 24, 2019, 09:04:48 pm »
0
2011-Q9-b-ii
Can someone please explain how did they get the answer as 18 litres? And like how do you know that you have to integrate (t)? Because I tried to sub 4 into both equations of liquid A and B and then subtract to get the answer as 4 litres? Help please!

Hawraa

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Re: Mathematics Question Thread
« Reply #4412 on: October 24, 2019, 09:08:02 pm »
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Hey there!

They earn half a cent per member per day, not half a dollar. This means they are correct in multiplying by $0.005 as opposed to the $0.50 that half a dollar would get you.

Hope this helps :)

But then would you do 0.5x1/2? But that would equal 0.25? Sorry I know it sounds stupid but I'm actually confused how to get half a cent?

fun_jirachi

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Re: Mathematics Question Thread
« Reply #4413 on: October 24, 2019, 09:46:43 pm »
+1
But then would you do 0.5x1/2? But that would equal 0.25? Sorry I know it sounds stupid but I'm actually confused how to get half a cent?

There are never stupid questions, ever. You can't know what you don't know, so don't be afraid to ask!

Recall that 100 cents make a dollar; this means that 1 cent is $0.01. Then, we halve it to get half a cent ie. $0.005 :) Does this make more sense?

2011-Q9-b-ii
Can someone please explain how did they get the answer as 18 litres? And like how do you know that you have to integrate (t)? Because I tried to sub 4 into both equations of liquid A and B and then subtract to get the answer as 4 litres? Help please!

You have to integrate here to find the volumes; you can't subtract the rates of change then multiply by the time taken. The rate of change given in the question is essentially just telling you how fast the water is coming out; it doesn't tell us anything about how much water is in the actual tank. And the answer is wrong; it's actually supposed to be 8 litres, not 18. There's a load of typos in the various sample answers, so just be wary of that :)
Failing everything, but I'm still Flareon up.

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Hawraa

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Re: Mathematics Question Thread
« Reply #4414 on: October 24, 2019, 09:55:03 pm »
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There are never stupid questions, ever. You can't know what you don't know, so don't be afraid to ask!

Recall that 100 cents make a dollar; this means that 1 cent is $0.01. Then, we halve it to get half a cent ie. $0.005 :) Does this make more sense?

You have to integrate here to find the volumes; you can't subtract the rates of change then multiply by the time taken. The rate of change given in the question is essentially just telling you how fast the water is coming out; it doesn't tell us anything about how much water is in the actual tank. And the answer is wrong; it's actually supposed to be 8 litres, not 18. There's a load of typos in the various sample answers, so just be wary of that :)

Yup, got it now. Thanks a lot 🌷

Coolmate

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Re: Mathematics Question Thread
« Reply #4415 on: November 05, 2019, 07:09:34 pm »
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Hi Everyone! :D

I am currently studying the topic: "Series and Sequences" and have come across both of these questions (questions are attached) and have no idea about how to go about solving them. Could someone please help me with them? --> btw, the question states:

"Find the value of the pronumeral in each arithmetic sequence"

Thanks in advance,
Coolmate 8)
« Last Edit: November 05, 2019, 07:11:05 pm by Coolmate »
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r1ckworthy

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Re: Mathematics Question Thread
« Reply #4416 on: November 05, 2019, 07:30:04 pm »
+2
Hi Everyone! :D

I am currently studying the topic: "Series and Sequences" and have come across both of these questions (questions are attached) and have no idea about how to go about solving them. Could someone please help me with them? --> btw, the question states:

"Find the value of the pronumeral in each arithmetic sequence"

Thanks in advance,
Coolmate 8)

Hey!
Arithmetic series have the following property (due to the common difference):
\[ T_2 - T_1 = T_3 - T_2 \]
We can use this to find the pro-numeral:
\[ (5k + 2) - 3 = 21 - (5k +2) \\ 5k + 2 -3 = 21 -5k -2 \\ 5k -1 = 19 - 5k \\ 10k = 20 \\ k = 2 \]
I'll let you have a go with the other question :)
Let me know if you need any more help!
« Last Edit: November 05, 2019, 07:37:19 pm by r1ckworthy »
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Re: Mathematics Question Thread
« Reply #4417 on: November 05, 2019, 07:46:52 pm »
0
Hey!
Arithmetic series have the following property (due to the common difference):
\[ T_2 - T_1 = T_3 - T_2 \]
We can use this to find the pro-numeral:
\[ (5k + 2) - 3 = 21 - (5k +2) \\ 5k + 2 -3 = 21 -5k -2 \\ 5k -1 = 19 - 5k \\ 10k = 20 \\ k = 2 \]
I'll let you have a go with the other question :)
Let me know if you need any more help!

Hi r1ckworthy,

Thankyou for your reply, I do have a couple of questions though. For the first one why didn't you times (5k+2) by -3? and for the second question (h) I wrote this as my working out and got a wrong answer of x = 11:
(h):
\[ (x+3) - x = (2x +5) - (x+3) \\ 3 = 2x + 5 - x - 3 \\ 6 = x + 5 \\ x = 11 \]

Could you please suggest what I have done wrong with my working out please?

Thanks again for your help!
Coolmate 8)
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r1ckworthy

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Re: Mathematics Question Thread
« Reply #4418 on: November 05, 2019, 07:58:56 pm »
+2
Hi r1ckworthy,

Thankyou for your reply, I do have a couple of questions though. For the first one why didn't you times (5k+2) by -3? and for the second question (h) I wrote this as my working out and got a wrong answer of x = 11:
(h):
\[ (x+3) - x = (2x +5) - (x+3) \\ 3 = 2x + 5 - x - 3 \\ 6 = x + 5 \\ x = 11 \]

Could you please suggest what I have done wrong with my working out please?

Thanks again for your help!
Coolmate 8)

Hey Coolmate!

As for your first question, I don't really need to multiply by -3, just subtract 3 from (5k + 2) as per the formula. As for your second question, you made an error on the third line of your working out. You should subtract 5 from 6 instead of add :), so it will look like this:
\[ (x+3) - x = (2x +5) - (x+3) \\ 3 = 2x + 5 - x - 3 \\ 6 = x + 5 \\ 6 \color{red}{- 5} = x \\ x = 1 \]

Hope that helps! Let me know if you need further help :)
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Re: Mathematics Question Thread
« Reply #4419 on: November 05, 2019, 08:04:52 pm »
+2
Hey r1ckworthy!

Thankyou so much, this makes a whole lot more sense and I am getting the questions right now! I like how you previously did the formula as:

T2 - T1 = T3 - T2

And for my second question...... that was such a silly mistake😂😂, thanks for clarifying this for me

Thanks again!
Coolmate 8)
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sharlt

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Re: Mathematics Question Thread
« Reply #4420 on: November 28, 2019, 03:44:40 pm »
0
Hi there,

I was wondering if I could have help with this question - thank you!

A bag contains 6 white, 7 red and 8 blue balls. Create a probability function table for the number of white balls selected when drawing two balls from the bag:

A) With replacement
B) Without replacement

RuiAce

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Re: Mathematics Question Thread
« Reply #4421 on: November 28, 2019, 10:26:40 pm »
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Hi there,

I was wondering if I could have help with this question - thank you!

A bag contains 6 white, 7 red and 8 blue balls. Create a probability function table for the number of white balls selected when drawing two balls from the bag:

A) With replacement
B) Without replacement
Can you please be more specific on where it is you're having trouble? Or alternatively provide some insight on what you tried thus far?

sharlt

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Re: Mathematics Question Thread
« Reply #4422 on: November 29, 2019, 02:04:37 pm »
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Ended up figuring it out - but thank you anyway!