368 views

### A bag contains 12 bals of different colours: 5 red, 4 blue and 3 yellow. What is the probability of not selecting a red ball

The probability of an event not happening is 1 minus the probability of the event happening. Five of the twelve balls are red so the probability of selecting a red ball is 5/12. The probability of not selecting a red ball is 1 - 5/12. Find a common denominator in order to calculate this subtraction: 1 - 5/12 = 12/12 - 5/12 = 7/12.

10 months ago

Answered by Laura, a GCSE Maths tutor with MyTutor

## Still stuck? Get one-to-one help from a personally interviewed subject specialist

#### 803 SUBJECT SPECIALISTS

£20 /hr

Degree: MMath Pure Mathematics (Masters) - St. Andrews University

Subjects offered:Maths, English Literature

Maths
English Literature

“I am an experienced mathematician with a personal approach to tutoring. I'm here to help you further your mathematical potential.”

£24 /hr

Degree: Biological Sciences with a Year in Industry/Research (Bachelors) - Imperial College London University

Subjects offered:Maths, Chemistry+ 1 more

Maths
Chemistry
Biology

£18 /hr

Degree: Veterinary Medicine (with Intercalated Year) (Bachelors) - Royal Veterinary College University

Subjects offered:Maths, Science+ 5 more

Maths
Science
Human Biology
English
Chemistry
-Personal Statements-

“Fourth year vet student and self-proclaimed science nerd, offering personalised tuition in the sciences, maths and English at all levels from 11+ to A Level/IB”

MyTutor guarantee

Currently unavailable: for new students

Degree: Post Doctoral Researcher in Mathematics (Other) - Exeter University

Subjects offered:Maths, Physics

Maths
Physics

“About me: I am a post doctoral researcher in mathematics at the University of Exeter. This means I am employed by the university to do research and help out with the lecturing and tutoring of undergraduates. I completed mymaths degree...”

MyTutor guarantee

### You may also like...

#### Posts by Laura

A bag contains 12 bals of different colours: 5 red, 4 blue and 3 yellow. What is the probability of not selecting a red ball

A musical instrument produces a sound wave with a frequency of 1000 Hz. The sound wave has a wavelength of 0.34 m in air. Calculate the speed of the sound wave in air.

The triangle ABC is such that AC=8cm, CB=12cm, angle ACB=x radians. The area of triangle ABC = 20cm^2. Show that x=0.430 (3sf)

Write down two reasons for using statistical models

#### Other GCSE Maths questions

Expand 5(2x-6)

A ladder 5m long is leaning up against a wall. The foot of the ladder is 3m from the wall. How high up the wall does the ladder reach?

Solve: (6x + 4)/(2x - 2) + 6 = 8

Solve the simultaneous equations x^2 + y^2 = 9 and x+ y = 2. Give your answer to 2.d.p

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this.