Solutions (2 Viewers)

[Pixydust*]

i was wondering if anybody can answer my question - if, during my exam, i correctly solved a problem, but being the idiot i am, cross out my solution and write another (incorrect) answer, will i still be awarded any marks for my correct answer? thank you

 

[Chris Lloyd]

No you wont get the points if you crossed it out.

For 10b.) i got t = 30. Not 30 / (2^1/2) or anything like that.

I found the area for y = x + 1/4 in the square (let that equal A1) i then got the area under x = y + 1/4 (let that equal A2). All of that is in terms of t.

I then did A1 - A2 = 1/2

Do the algebra and P(meeting) = 1/2 when t = 30. The answer makes sense as well considering they have a space of an hour. Think about it, how could they possible either meet each other or not if they wait around for only ~17 mins?

Say Person 1 (P1) came at 12 and then left at 12:30. There is a 50% chance that P2 would come between 12 and 12:30 or between 12:30 and 1. Therefore t must equal 30. But of course we had to prove that mathematically.

 

[slinky_cumquat]

well i failed this exam..damnit!

 

[instantGRAVY]

thanks MarsBarz much appreciated

 

[jennylim]

No you wont get the points if you crossed it out.

For 10b.) i got t = 30. Not 30 / (2^1/2) or anything like that.

I found the area for y = x + 1/4 in the square (let that equal A1) i then got the area under x = y + 1/4 (let that equal A2). All of that is in terms of t.

I then did A1 - A2 = 1/2

Do the algebra and P(meeting) = 1/2 when t = 30. The answer makes sense as well considering they have a space of an hour. Think about it, how could they possible either meet each other or not if they wait around for only ~17 mins?

Say Person 1 (P1) came at 12 and then left at 12:30. There is a 50% chance that P2 would come between 12 and 12:30 or between 12:30 and 1. Therefore t must equal 30. But of course we had to prove that mathematically.

actually, since the first one (15 mins) leaves a 7/16 probability that they will meet, it really does make sense that 17 mins is a 50% (8/16) chance of meeting. you draw the lines and subtract the area of the triangles from the unit square.

i think t=1/2 (which is what it must be) would lead to a 3/4 chance of xuan and yvette meeting.

1 - (1/2)^2 = 3/4.

My reasoning anyway.

 

[princess M]

i was wondering if anybody can answer my question - if, during my exam, i correctly solved a problem, but being the idiot i am, cross out my solution and write another (incorrect) answer, will i still be awarded any marks for my correct answer? thank you

umm. my maths teacher has been marking the HSC for a looooooong time and he told us that u get alllll the marks even if u crossed it out.
as long as u havent vigorously scribbled over it, and its still readable, the markers will actually treat it as the only answer u put- hence ignoring ur incorrect answer.
hmm. thats wat we were told- and im quite sure its correct.
hope that helps!

 

[Pixydust*]

umm. my maths teacher has been marking the HSC for a looooooong time and he told us that u get alllll the marks even if u crossed it out.
as long as u havent vigorously scribbled over it, and its still readable, the markers will actually treat it as the only answer u put- hence ignoring ur incorrect answer.
hmm. thats wat we were told- and im quite sure its correct.
hope that helps!

thank you so much!! either way i don't mind because i know i tried my best anyway but it would be nice to scrape in a few extra marks, considering i did know what i was doing, i just didn't...know..i....did - thanks again!

 

[Srixon]

yeah as long as they can read it not all scribled out as they have to read everything our teacher said and he has marked the hsc before