Probability of doing both is 1/6 x 1/5 = 1/30. We need to subtract this because we have considered the first two probabilities as independent events. But when we consider that they could happen at the same time, this would essentially reduce the probability that someone could win (If they have already won from rolling a 1, we cannot include them then spinning a 1 as an increase to the probability of them winning, they would win anyway!).Another way to think of it, is you have duplicated a probability. We have already included getting a 1 on a roll, and a 1 on a spin, so we need to remove that duplication!
Could you do a video giving a strategy for the really hard vector questions (like Nov 2018, Paper , Q21) where you need to use 2 algebraic constants and compare the vectors, please?
I have managed to work it out, but took an absolute age, as it doesn't teach this anywhere, so need a strategy that I can repeat, for speed.
I could work one out myself, but rather pressed for time, and wondered if there was a particular way that you teach it.
Just discovered that the grade boundary for a 9, on that paper, was 59/80!!! It was a bit of a corker
Cumulative frequency is plotted from end of each group, is a smooth curve, and is extended to zero, at the value for the beginning of the first group eg. first group is (20-40 years) so the end of the curve would be at 20 on x axis and zero on y
are frequency polygons plotted from the mid-point of the group?
frquency density is a histogram
Trying to get my head around which is mid-point and which is end of group!!!
We didn't do any of this, in my adult class, as no time, so self-taught. Eek
It will get easier after paper 1, as you'll know which one/ones have come up, and so there will be less to remember for papers 2 and 3.
It might also be worth just looking over the topic 'Averages from a Table' if you haven't already, as a 'finding the mean from a frequency table' question will also look very similar!
Hi Laura, hope you are doing fine. Could you do a short video explanation on Venn diagram where there is x as unknown (algebraic venn diagram) if possible please. Thank you.
Do you have any examples of a circle theorem questions using the angle at the centre/circumference:
where the central angle is 180 degrees, and it is not the diameter, so that I can practice identifying this? I imagine that they are less easy to identify.
where there are not two obvious "arrowheads". Sometimes they cross in a strange way and are less easy to spot. Finding it hard to find any examples, myself
Hi Laura,
COuld you look at this Q, please?
I can get both down to
4(m^2 -n^2+m+n)
, so they are equal, but how do I prove the final factorisation?
Thanks
Sarah
Hi Laura,
Can you explain why the "roll a 1 or spin a 1 or both" is 1/6 + 1/5 MINUS 1/30?
I have the fractions but cannot get my head around why you subtract the 1/30.
Just can't get my head to work it out. SO annoying!!!
Thanks
Sarah
Thanks
Afternoon, Laura.
Could you do a video giving a strategy for the really hard vector questions (like Nov 2018, Paper , Q21) where you need to use 2 algebraic constants and compare the vectors, please?
I have managed to work it out, but took an absolute age, as it doesn't teach this anywhere, so need a strategy that I can repeat, for speed.
I could work one out myself, but rather pressed for time, and wondered if there was a particular way that you teach it.
Just discovered that the grade boundary for a 9, on that paper, was 59/80!!! It was a bit of a corker
Thanks
Sarah
What does "Time Series" mean, on curriculum lists? Keeps appearing but no-one has questions saved under that title, so don't know what it is.
Thanks, Laura.
Sarah
Hi Laura,
Could I check the following re stats graphs:
Cumulative frequency is plotted from end of each group, is a smooth curve, and is extended to zero, at the value for the beginning of the first group eg. first group is (20-40 years) so the end of the curve would be at 20 on x axis and zero on y
are frequency polygons plotted from the mid-point of the group?
frquency density is a histogram
Trying to get my head around which is mid-point and which is end of group!!!
We didn't do any of this, in my adult class, as no time, so self-taught. Eek
Thanks
Sarah
Hi Laura, hope you are doing fine. Could you do a short video explanation on Venn diagram where there is x as unknown (algebraic venn diagram) if possible please. Thank you.
Hi Laura,
Do you have any examples of a circle theorem questions using the angle at the centre/circumference:
where the central angle is 180 degrees, and it is not the diameter, so that I can practice identifying this? I imagine that they are less easy to identify.
where there are not two obvious "arrowheads". Sometimes they cross in a strange way and are less easy to spot. Finding it hard to find any examples, myself
Thanks, Sarah
can you show how to answer these questions, thanks
hello, can you show the working for this question, thanks.