Number Q. (2 Viewers)

[Smile12345]

Hello All...

How do you do...

Q. The value of shares in a large company fell by 2.7% from opening time on Monday morning until closing time the same day. The value of the shares than fell by 3.09% over the corresponding time period on Tuesday.

Express the value of the shares at closing time on Tuesday as a percentage of the value at opening time on Monday.


Thanks in advance.

 

[HeroicPandas]

These questions are super hard! I'll give it a go:

So the value of the company's shares are falling each day

After monday, shares have fallen 2.7% (0.027 as decimal)
After tuesday, shares have fallen 3.09% (0.0309 as decimal)

Let A be the value of shares

Opening time, the value of the shares is A
After monday, the value of shares decreased by 2.7%, so it should be: (1 - 0.027)A = (0.973)A

Beginnging of tuesday, the value of the shares is: (0.973)A
After tuesday, the value of the shares decreased by 3.09%, so it should be [(0.973)A](1 - 0.0309) = [(0.973)A](0.9691) = 0.9429343A = 0.94A (2dp)

So after tuesday (closing time on tuesday) the value of the share is 0.94A

% =

So 94%?

(sorry if it looks unpleasant, i like to work with decimals)

 

[HSC2014]

Mhm...
97.3% x 96.91% = 94.29% in short (though heroic has explanations)

 

[Smile12345]

Mhm...
97.3% x 97.91% = 94.29% in short (though heroic has explanations)

Yup.... Thanks... Could you do as progressive?

Say: Monday Closing 97.3% (of original)... Then Tues opening: 97.3% and Tues closing: 97.3% - 3.09% of 97.3% --> 94.29%

 

[Smile12345]

These questions are super hard!

Sorry HeriocPandas.... I'm obviously not as smart as you.

Thanks for your help though (you don't have to).

 

[Menomaths]

Mhm...
97.3% x 97.91% = 94.29% in short (though heroic has explanations)

There's something wrong in your calculation

 

[HeroicPandas]

Sorry HeriocPandas.... I'm obviously not at smart as you.

Thanks for your help though (you don't have to).

We are equal in 2U maths (these types of questions seem hard to me, but doing it doesnt seem too bad)

 

[HSC2014]

There's something wrong in your calculation

Ah yeah thanks edited

 

[Smile12345]

Ah yeah thanks edited

Could I do it as I suggested??

 

[Menomaths]

Could I do it as I suggested??

Your method is also correct and the way I did it so it's even more correct

1-2.7% = 97.3%
97.3%-3.07% = 94.21%

 

[HSC2014]

Could I do it as I suggested??

I don't quite understand your method. You cant just minus 3.09% out of no where :S
Someone explain to me? Im scrub with math

 

[Smile12345]

Your method is also correct and the way I did it so it's even more correct

1-2.7% = 97.3%
97.3%-3.07% = 94.21%

What's the difference? Apart from the fact you wrote 3.07 instead of 3.09%???

 

[Smile12345]

I don't quite understand your method. You cant just minus 3.09% out of no where :S
Someone explain to me? Im scrub with math

I'm not.... It's just the % decrease in the 2nd day.

 

[HSC2014]

I'm not.... It's just the % decrease in the 2nd day.

Nevermind, I realised where my thinking was going in loops. Yes your way is correct, though i wouldn't recommend it (minus way).

 

[HeroicPandas]

Your method is also correct and the way I did it so it's even more correct

1-2.7% = 97.3%
97.3%-3.09% = 94.21%

HSC2014 and I have different answers to you and Smile12345

The share value is 97.3% of original after Monday

IF share value is then reduced by 3.09% (at the end of Tuesday), then 3.09% of the remaining 97.3% of the share value is LOST!

SO, then 96.91% of the share value of 97.3% is LEFT!

So, 97.3% x 0.9691 = 94.29% (2dp)

Do you understand? Subtracting is different

 

[Menomaths]

Oh crap...Once again I'll just back off from the maths forum

 

[HeroicPandas]

Oh crap...Once again I'll just back off from the maths forum

No!!! dont leave!!!! what if this exact question popped up in the HSC? then u may have lost some marks in ur 2U exam!

 

[Smile12345]

HSC2014 and I have different answers to you and Smile12345

The share value is 97.3% of original after Monday

IF share value is then reduced by 3.09% (at the end of Tuesday), then 3.09% of the remaining 97.3% of the share value is LOST!

SO, then 96.91% of the share value of 97.3% is LEFT!

So, 97.3% x 0.9691 = 94.29% (2dp)

Do you understand? Subtracting is different

Yes - with my post.... I wrote that answer....

"Say: Monday Closing 97.3% (of original)... Then Tues opening: 97.3% and Tues closing: 97.3% - 3.09% of 97.3% --> 94.29%"

(Sorry I didn't realise Menomaths had made a small error)

 

[Smile12345]

I believe I have the same answer.... Just a slightly different way...

Oh well....

 

[HeroicPandas]

Yes - with my post.... I wrote that answer....

"Say: Monday Closing 97.3% (of original)... Then Tues opening: 97.3% and (from here onwards)Tues closing: 97.3% - 3.09% of 97.3% --> 94.29%"

(Sorry I didn't realise Menomaths had made a small error)

I see, the dash in that phrase confused me because i thought it was a minus sign lol