Question

Last week the number of bacteria in a petri dish was 2.25×102. This week the number of bacteria in the petri dish is 2.75×105. How many times more bacteria are in the petri dish this week? Round the decimal to the nearest tenth.

Answer 1

There are

1.2

× 10

3

times more bacteria in the petri dish this week compared to last week.

Explanation:

Answer 2

There are 0.3 more bacteria in the Petri dish

Explanation:

To do the problem we first have to do the corresponding multiplications

2.25 * 102 = 229.5

2.75 * 105 = 288.75

Now that we have both results we have to make the number of bacteria in the second plate divided by the number of bacteria in the first plate and in this way find out how many times it grew

288.75/229.5= 1.258

if we round to the nearest tenth

1.258 = 1.3

To find out how many more bacteria there are on the first plate, we have to challenge it 1

1.3 - 1 = 0.3

There are 0.3 more bacteria in the Petri dish