[Closed] Help - A 10 year old's maths question

@miketually

a) P(two_orange_sweets_in_a_row)=(6/n){5/(n-1)}=1/3
90 = n(n-1)
n^2-n-90 = 0

b) n=10 using the quadratic equation formula. Must admit I had to work that out.

How many sweets do I get?

@curiousyellow

You get 8; she's already eaten two 🙂

OK maths fans how about this one...
There was an old woman who lived in a shoe. She had 9 children at regular intervals of 15 months. The oldest is now six times as old as the youngest. How old is the youngest?
(for 12 and 13 year olds)

@I_dib_dab

20 months old

(8 x 15) / 6

b) n=10 using the quadratic equation formula. Must admit I had to work that out.

How many sweets do I get?

Not as many as you would if you'd simplified the equation to (n-10)(n+9) = 0, from whence you'd find the two answers for n are +10 and -9

And since -9 is clearly not an answer in this case, n=10

^
found the teacher's pet...

aka the boy with most sweets.

@stevehine nope...try again