Understanding Percentages

Professor Bob introduces the concept of percentages, explaining them as fractions with a denominator of 100. He demonstrates how to express data using percentages and fractions, and provides examples of calculating percentages from numbers. The video also covers converting data to percentages and vice versa. Professor Bob explains discounts and price increases, showing how to calculate them using percentages. The lesson concludes with a summary of the key points discussed.

What is a percentage?

• A fraction with a numerator of 10

• A fraction with a denominator of 100

• A fraction with a denominator of 10

• A fraction with a numerator of 100

How can the fraction 2/100 be represented as a percentage?

• 200%

• 20%

• 2%

• 0.2%

In a survey of 100 students, how many expressed a positive opinion if 81% were satisfied?

• 100 students

• 7 students

• 12 students

• 81 students

What color represents the students who did not express any opinion in the square diagram?

• Yellow

• Blue

• Green

• Red

How many students chose lasagna if 15% of 300 students made that choice?

• 15 students

• 45 students

• 60 students

• 30 students

What is the percentage of students who practice a sport if 16 out of 25 students do so?

• 64%

• 16%

• 25%

• 32%

If 48 is 20% of a number, what is the original number?

• 240

• 120

• 48

• 96

What is a discount?

• An increase in price

• A reduction in price

• A fixed price

• A tax on the price

If a video game costs 35 euros and has a 20% discount, what is the final price?

• 25 euros

• 28 euros

• 35 euros

• 30 euros

If a pair of shoes cost 49 euros last year and the price increased by 9%, what is the new price?

• 53.41 euros

• 54 euros

• 49 euros

• 50 euros