The brain definitely isn't what it used to be but my 9 year old has been given a maths probabilty question and he and I are both struggling but I'm not sure if he has not been given the full question, here goes:
In a multipack of crisps there's a 7 in 10 chance of getting roast chicken, 1 in 5 of getting salt and vinegar therefore what is the proabability of getting ready salted? I'm thinking he should've been told the total in the bag originally - any shouts greatly appreciated?
Maths help please...
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Maths help please...
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Dave W wrote: "The brain definitely isn't what it used to be but my 9 year old has been given a maths probabilty question and he and I are both struggling but I'm not sure if he has not been given the full question, here goes:
In a multipack of crisps there's a 7 in 10 chance of getting roast chicken, 1 in 5 of getting salt and vinegar therefore what is the probability of getting ready salted? I'm thinking he should've been told the total in the bag originally - any shouts greatly appreciated?"
I think that there is at least one piece of information missing: I assume that the multipack only contains Roast Chicken, Salt & Vinegar and Ready Salted. If so to get to the answer you have to consider that the total probability is 10/10 so if there is a 7/10 chance of chicken and 1/5 ( which is the same as 2/10) of getting Salt & Vinegar then that only leaves 10 – 7 – 2 = 1/10 chance of getting Ready Salted. You don't actually need the number of bags in the multipack.
Have been on the Guinness, but I think that’s right!
In a multipack of crisps there's a 7 in 10 chance of getting roast chicken, 1 in 5 of getting salt and vinegar therefore what is the probability of getting ready salted? I'm thinking he should've been told the total in the bag originally - any shouts greatly appreciated?"
I think that there is at least one piece of information missing: I assume that the multipack only contains Roast Chicken, Salt & Vinegar and Ready Salted. If so to get to the answer you have to consider that the total probability is 10/10 so if there is a 7/10 chance of chicken and 1/5 ( which is the same as 2/10) of getting Salt & Vinegar then that only leaves 10 – 7 – 2 = 1/10 chance of getting Ready Salted. You don't actually need the number of bags in the multipack.
Have been on the Guinness, but I think that’s right!
If that was the question the child was given, it doesn't strike me as a reasonable sort of question for a 9-year old to be given. At that age I would have thought that the total number of packs would have been useful.
Having said that, good answer Tyzot!
Having said that, good answer Tyzot!
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It's a perfectly reasonable maths question for a 9 year old but you are right that one piece of information was missing:
He needed to be told that there were only 3 flavours in the multipack, thus leaving only one variable.
Without that bit of info he could assume that the multipack also included cheese & onion & therefore, with two variables no definitive answer could be given.
He needed to be told that there were only 3 flavours in the multipack, thus leaving only one variable.
Without that bit of info he could assume that the multipack also included cheese & onion & therefore, with two variables no definitive answer could be given.
