## O-Level Elementary Math

PSLE marks the graduation of Primary school students and their entry into Secondary schools as teenagers. Discuss all issues about Secondary schooling here.
kennethTutor
OrangeBelt
Posts: 39
Joined: Mon Jul 13,
Total Likes:2

### Re: O-Level Elementary Math

RedAngryBird wrote:PLS HELP IN THIS QUESTION!!!!!
The Probability that Lisa and Meiling will pass a driving test are 2/3 and 3/8 respectively. Find the probability that

a)both Lisa and Meiling will pass the test.
b)only one of them will pass the test.
There is only two possible outcomes, either pass or fail the test.

P(Lisa pass) = 2/3
P(Lisa fail) = 1 - 2/3 = 1/3

P(Meiling pass) = 3/8
P(Meiling fail) = 5/8

a) P(Lisa and Meiling pass) = 2/3 x 3/8 = 1/4

b) Since only one pass, the other person will fail. So it is possible that Meiling pass and Lisa fail OR Lisa pass and Meiling fail.

P(only one pass) = 3/8 x 1/3 + 2/3 x 5/8 = 13/24

Suz855
BlueBelt
Posts: 350
Joined: Wed May 13,
Total Likes:2

### Re: O-Level Elementary Math

Need help with the following
A car and a motorcycle travelled from Bugis to Kallang and the speed-time graph of their journey is shown below. Both vehicles left Bugis together and took the same route. Find
(c) the time t at which the motorcycle overtook the car.
(You may assume that t > 2)

[img][IMG]http://i65.tinypic.com/6hny9d.gif[/img] [/img]

questionable_i
BrownBelt
Posts: 535
Joined: Sat Oct 10,
Total Likes:1

### Re: O-Level Elementary Math

Can anyone help me with these two questions?
1. It is given that O is the origin, A is the point (2,1) and B is the point (12,10).
(a) Find the equation of line AB
(b) A straight line l is parallel to the line AB and passes through the origin. Write down the equation of the line l

2. The coordinates of the point P and Q are (-2,7) and (3,-6) respectively.
(a) Find the equation of the line joining the points P and Q.
(b) Hence, find the coordinates of the point where the line PQ crosses the x-axis.

Jmaths.SG
YellowBelt
Posts: 19
Joined: Fri Apr 01,

### Re: O-Level Elementary Math

questionable_i wrote:Can anyone help me with these two questions?
1. It is given that O is the origin, A is the point (2,1) and B is the point (12,10).
(a) Find the equation of line AB
(b) A straight line l is parallel to the line AB and passes through the origin. Write down the equation of the line l

Jmaths.SG
YellowBelt
Posts: 19
Joined: Fri Apr 01,

### Re: O-Level Elementary Math

questionable_i wrote: 2. The coordinates of the point P and Q are (-2,7) and (3,-6) respectively.
(a) Find the equation of the line joining the points P and Q.
(b) Hence, find the coordinates of the point where the line PQ crosses the x-axis.

Jmaths.SG
YellowBelt
Posts: 19
Joined: Fri Apr 01,

### Re: O-Level Elementary Math

Suz855 wrote:Need help with the following
A car and a motorcycle travelled from Bugis to Kallang and the speed-time graph of their journey is shown below. Both vehicles left Bugis together and took the same route. Find
(c) the time t at which the motorcycle overtook the car.
(You may assume that t > 2)

[img][IMG]http://i65.tinypic.com/6hny9d.gif[/img] [/img]
Acceleration of MC
= 20/4
= 5m/s^2

At time = t,

Dist (Car)
= (1/2)(2)(20) + (t-2)(20)
= t-20

Dist (MC)
= (1/2)(acceleration)(t^2)
= (1/2)(5)(t^2)
= (5/2)t^2

When MC overtakes Car,

Dist (MC) = Dist (Car)

(5/2)t^2 = t-20
t^2 - 8t + 8 = 0

Using x = [-b +or- (b^2 - 4ac)^(1/2) ] / 2a

t = 6.83 (rounded to 2 dec places) or 1.17 (rounded to 2 dec places; rejected since t<2).

Ans: 6.83 sec

KSP2013777
OrangeBelt
Posts: 92
Joined: Fri Dec 28,

### Re: O-Level Elementary Math

Thank you.

sundarshoba
KiasuNewbie
Posts: 9
Joined: Fri Mar 30,

### Secondary Maths Question

144 boys and 264 girls on a field trip to CC's were divided into the maximum no of teams, with each team having equal no of boys and girls. If each team visited a different CC, how many CC's were visited and how many members were there in a team? Thanks

OrangeBelt
Posts: 81
Joined: Mon Aug 24,
Total Likes:3

### Re: O-Level Elementary Math

Thank you.
Hi see the solution in the photo.

Please let us know if you need more support in Math or other subjects. Our academy have teachers from RGS/NYGH/ACJC/GEP/top schools, we are willing to help you!

OrangeBelt
Posts: 81
Joined: Mon Aug 24,
Total Likes:3