N sweets in a bag. 6 sweets are orange. The rest are yellow. Hannah takes a random sweet from the bag and eats it. She then takes another random sweet from the bag & eats it. The probability Hannah eats 2 orange sweets is 1/3. Show n^2 - n - 90 = 0.

It's a probability equation. The probability of getting an orange sweet the first time is 6/n. The probability of getting an orange sweet the second time is 5/n-1Times those together to get the probability of 2 orange sweets: 6/n x 5/n-1 = 30/n2 - n This we're told equals a 1/3: 1/3 = 30/n2 - n (then times the bottoms up)n2 - n = 90 (take the 90 over to the left)n2 - n - 90 = 0

Answered by Hannah B. Maths tutor

3224 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How do I know which trig formula to use in the exam?


ABC is an isosceles triangle such that AB = AC A has coordinates (4, 37) B and C lie on the line with equation 3y = 2x + 12 Find an equation of the line of symmetry of triangle ABC. Give your answer in the form px + qy = r where p, q and are integers (5


Given a right-angled triangle with an angle of 35 degrees and an Opposite side of 12cm, calculate the length of the hypotenuse to 3 significant figures.


Solve the equation to find the value of t. (5t+3)/4=1


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences