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# hard question watch

1. There are n sweets in a bag. Six of the sweets are orange. The rest of the sweets are yellow.Hannah takes a sweet from the bag. She eats the sweet. Hannah then takes at random another sweet from the bag. She eats the sweet.The probability that Hannah eats two orange sweets is 1/3. Show that n²-n-90=0
2. (Original post by santosh1)
There are n sweets in a bag. Six of the sweets are orange. The rest of the sweets are yellow.Hannah takes a sweet from the bag. She eats the sweet. Hannah then takes at random another sweet from the bag. She eats the sweet.The probability that Hannah eats two orange sweets is 1/3. Show that n²-n-90=0
If there were initially 50 sweets in the bag would you know how to calculate the probability that the first sweet was orange and the second sweet was orange?

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3. (Original post by gdunne42)
If there were initially 50 sweets in the bag would you know how to calculate the probability that the first sweet was orange and the second sweet was orange?

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Show that n²-n-90=0
i know that n=10
10²-10-90=0
100-10-90=0
4. (Original post by santosh1)
Show that n²-n-90=0
i know that n=10
10²-10-90=0
100-10-90=0
Sure n=10 is the solution to the equation
However that does not answer the question the edexcel examiner has asked you which was to show that equation is true in the first place.

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5. (Original post by gdunne42)
Sure n=10 is the solution to the equation
However that does not answer the question the edexcel examiner has asked you which was to show that equation is true in the first place.

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anyway can you answer this please???

ABC is a triangle.
PQ are the midpoints of AB and AC.
Show that PQ is parallel to BC and 1/2 its length
6. (Original post by santosh1)
There are n sweets in a bag. Six of the sweets are orange. The rest of the sweets are yellow.Hannah takes a sweet from the bag. She eats the sweet. Hannah then takes at random another sweet from the bag. She eats the sweet.The probability that Hannah eats two orange sweets is 1/3. Show that n²-n-90=0
well the probability of taking an orange sweet must be 6/n

she then eats as sweet, so the probability of taking another orange sweet is 5/(n-1)

so the probability that both of these things will happen is (6/n) x 5/(n-1)

this is n2-n-30

we are told that the probability that hanna eats two oranges is 1/3, which means that this must equal 1/3: so n2-n-30=1/3

if we multiply both sides by 1/3 it equals n2-n-90
7. (Original post by santosh1)
well the probability of taking an orange sweet must be 6/n

she then eats as sweet, so the probability of taking another orange sweet is 5/(n-1)

so the probability that both of these things will happen is (6/n) x 5/(n-1)

this is n2-n-30
No, it's 30 / (n(n-1))
8. (Original post by santosh1)
anyway can you answer this please???

ABC is a triangle.
PQ are the midpoints of AB and AC.
Show that PQ is parallel to BC and 1/2 its length
You could show this with vectors. Have you learnt about vectors yet?

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