GCSE Secondary Maths Age 13-17 - Ratio, Proportion & Rates of Change: Geometric Progression - Explained

The video tutorial explores the exponential growth of bacteria in two flasks, A and B. It demonstrates how the population in flask A forms a geometric progression with a common ratio of 1.5. The tutorial calculates the population on the 10th and 6th days to find a multiplier, k. It also sketches a graph comparing the growth rates in both flasks, highlighting the faster growth in flask A due to a higher rate of increase. The tutorial emphasizes understanding geometric progressions and exponential growth.

What is the initial number of bacteria in flask A at the start of day one?

• 500

• 1000

• 2000

• 1500

What is the common ratio in the geometric progression of bacteria growth in flask A?

• 1.2

• 1.3

• 1.5

• 1.4

How many bacteria are there in flask A at the start of day three?

• 1500

• 2000

• 2500

• 2250

What is the value of k, the growth factor from day six to day ten in flask A?

• 6.0

• 5.0625

• 4.5

• 5.5

What is the population of bacteria in flask A at the start of the 10th day?

• 28,000

• 32,000

• 40,000

• 38,443

At what rate does the bacteria population in flask B grow per day?

• 30%

• 25%

• 35%

• 20%

Which flask shows a faster rate of bacteria growth?

• Flask A

• Flask B

• Both grow at the same rate

• Cannot be determined