VCE Maths questions help (1 Viewer)

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
Find the first four terms of the geometric sequence where the 6th term is 243 and the 8th term is 2187
How would this be done?
 

InteGrand

Well-Known Member
Joined
Dec 11, 2014
Messages
6,109
Gender
Male
HSC
N/A
How do you get the -1/6 for the inverse?
He divided by the determinant of the matrix.

Of course, since the original matrix is diagonal, you can invert it by simply inverting (taking the reciprocal of) each diagonal entry.
 

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
Three coins are tossed. The probability of at least one head is?
How would this be worked out?
 

kawaiipotato

Well-Known Member
Joined
Apr 28, 2015
Messages
463
Gender
Undisclosed
HSC
2015
Do you know how to find the probability if we asked for only one head? How about two heads? Three heads?

At least one head means one head, two heads or three heads.
So you just need to add up the probability of finding one head, two heads and three heads together.

(Alternatively, you can compute 1 - Pr(no heads). Can you see why?).
 

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
Prepaid rent = $4200
yearly rent was paid on the 1st of march
To calculate the rent expense for december, 2013
Would it be $4200/2 = $2100, because march - december is 10 months, and 12 - 10 = 2 months?
 

He-Mann

Vexed?
Joined
Sep 18, 2016
Messages
278
Location
Antartica
Gender
Male
HSC
N/A
5/10/17
2^x = 7
How would you solve for x without a calculator using logarithms?
if you want the exact value of x;
take the log of both sides to get log(2^x)=log(7)
now apply the rule log(a^b)=blog(a) on the LHS to get xlog(2)=log(7)
hence x=log(7)/log(2)
put this on the calc if you want an approximation
6/10/17
10^x = 2
Would x = log(2)/log(10)?
Someone replied "yes"
28/10/17
2^(1-x) = 18
How would you solve this equation in a tech-free exam?
Give a demonstration of how you would do it.
 
Last edited:

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
A shop has presented the following extract from its balance sheet as at 31 December 2015
Current assets: Prepaid rent expense: $1800

The yearly rent was paid in advance on 1 October 2015. The business prepares financial reports monthly, and the next balance day occurs on 31 January 2016

How would you calculate rent expense for January 2016?
 

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
jack attends training 5 days per week
If jack runs one day, the probability that he will run again the next day = 4/5
If jack does not run one day, the probability that he will not run the next day = 3/4
Suppose jack runs one day:

a. Find pr(jack runs the next day)
b. Find pr(jack runs the day after that)
c. Find pr(jack runs exactly twice in the next 3 days)

Thanks
 

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
The probability that a student studies maths = 2/3
The probability that a student studies german = 3/10
The probability that a student studies maths and does not study german = 7/15
Find pr(a randomly chosen student does not study either maths or german)

P(m'u g') = p(m') + p(g') - p(m' and g') = 1/3 + 7/10 - 7/30
= 4/5
Is this correct?

If not, how would it be worked out?
 

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
The probability that a student studies maths = 2/3
The probability that a student studies german = 3/10
The probability that a student studies maths and does not study german = 7/15
Find pr(a randomly chosen student does not study either maths or german)

P(m'u g') = p(m') + p(g') - p(m' and g') = 1/3 + 7/10 - 7/30
= 4/5
Is this correct?

If not, how would it be worked out?
Bump
Confused with probability
 

boredsatan

Member
Joined
Mar 23, 2017
Messages
572
Gender
Male
HSC
1998
P(a u b) = P(a) + P(b)
P(a u b) = P(a) + P(b) - P(a and b)
which formula is correct?
I see both formulas being used in calculations
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top