Ratios and Probabilities in Counters

In this video, Gary explains a math problem from the Edexcel Higher Tier Paper 2018, focusing on ratios and probabilities. The problem involves calculating the probability of selecting a red counter from a bag containing red, blue, and purple counters. Gary walks through the problem, explaining the ratio of red to blue counters and the probability of selecting a purple counter. He demonstrates how to calculate the probability of selecting a red counter by using the given ratios and probabilities, ultimately simplifying the answer to 3/25. The video concludes with a call to action for viewers to like and subscribe.

What is the main topic discussed in the video?

• Geometry problems

• Algebraic equations

• Probability and ratios

• Calculus concepts

What is the ratio of red counters to blue counters?

• 1 to 5

• 3 to 17

• 2 to 3

• 4 to 9

What is the probability of picking a purple counter?

• 0.5

• 0.2

• 0.8

• 0.3

If the probability of picking a purple counter is 0.2, what is the probability of picking a red or blue counter?

• 0.8

• 1.0

• 0.2

• 0.5

How do the ratios of counters relate to their probabilities?

• They are unrelated

• They are inversely proportional

• They are equal

• They are directly proportional

What is the total of the ratio 3 to 17?

• 20

• 40

• 10

• 30

What fraction represents 0.8?

• 2/3

• 4/5

• 1/2

• 3/4

What is the probability of picking a red counter?

• 3/25

• 1/5

• 1/4

• 2/5

What is the first step in calculating the probability of picking a red counter?

• Convert 0.8 to a fraction

• Add the ratios

• Subtract the ratios

• Multiply the ratios

What is the simplified form of 12/100?

• 2/5

• 3/25

• 1/10

• 1/5