The Hard Grade 9 Questions Thread 2019

Select a counter at random from one of two bags:
black bag contains 9 counters : 2 red, 3 green & 4 blue.
white bag contains 12 counters : 5 red, 4 green & 3 blue.

P(choose black bag) = 1-P(choose white bag) = 4/9

Question :
Given that the selected counter is blue, what is the probability that it came from the white bag?

116/729

Triangle OAB
vector OA = a
vector OB = b

M is point on AB so that AM:MB = 1:2
P is point on OM so that OP:PM = 3:4

N is point on OB so that AP produced meets OB at N

ON:NB = x:y
Find smallest possible integers for values x,y.

Is it 1:4, as ON=0.2b and NB= 0.8b ?

no. show your working?

This is probably the hardest "official" question that I've seen for 9-1. It's confusing and badly worded so it's no surprise that it isn't in any of the Edexcel specimen papers anymore:

any predictions for AQA
Blood brothers
Christmas carol
Romeo and Juliet
Love and relationship poem

A) .15 = x
15.15= 100x
15=99x
X=5/33

B) 5x2 =10
5^n * 2^n.= 10 x 10^(N-1)
So 1*10^10
Therefore at least 1 * 10^180

Cool. And the last part ... why is Hugo's statement incomplete?

Yes. Nice one.

116/729

no. show your working?

I'll kick things off with one that I've posted the last 2 years and was done badly in both threads:




The value of is 32.123 degrees correct to 3 decimal places. The value of $y$ is 62.425 degrees correct to the nearest 0.005 degrees.

By considering bounds, find the value of to a suitable degree of accuracy. You must show all of your working.

Not gonna show all working but 0.851 ( 3 sf)