Answer:
There will be 32805 dandelions after 3 weeks
Step-by-step explanation:
To determine number of dandelions after 3 weeks
1 week = 7 days
∴ 3 weeks = 3 × 7 days = 21 days
Hence, we will determine the number of dandelions after 21 days.
From the question,
The number of dandelions growing on the lawn triples every 3 days and if the lawn started out with 15 dandelions,
Then, After 3 days, there will be 3 × 15 dandelions = 45 dandelions
After 6 days, there will be 3 × 45 dandelions = 135 dandelions
After 9 days, there will be 3 × 135 dandelions = 405 dandelions
After 12 days, there will be 3 × 405 dandelions = 1215 dandelions
After 15 days, there will be 3 × 1215 dandelions = 3645 dandelions
After 18 days, there will be 3 × 3645 dandelions = 10935 dandelions
After 21 days, there will be 3 × 10935 dandelions = 32805 dandelions
Hence, there will be 32805 dandelions after 3 weeks.
