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

3511 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

What is the cosine rule and when can it be used?


What is the equation of a straight line? Describe what all the terms within the equation do.


How would you solve a simultaneous equation?


If a train leaves for a 130 mile journey at 1.30pm, and travels at a constant speed of 50 miles per hour, at what time will it arrive?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences