Question

В пруду растут кувшинки. за сутки кувшинок в пруду увеличивается в два раза . через 20 суток пруд полностью покрылся кувшинками. через сколько суток пруд был покрыт кувшинками наполовину?

Answer 1

На 20-е сутки весь пруд покрыт кувшинками, значит половина пруда была покрыта в предыдущий день. Ответ: 19 суток.

Answer 2

Calculating the Growth of Water Lilies in a Pond

To calculate the number of days it took for the pond to be half-covered with water lilies, we can use the information provided.

Given: - Water lilies in the pond double in number every day. - It took 20 days for the pond to be completely covered with water lilies.

Solution:

To find out how many days it took for the pond to be half-covered with water lilies, we can work backwards from the day the pond was fully covered.

1. Determine the Rate of Growth: - The water lilies double in number every day.

2. Calculate the Number of Days for Half Coverage: - If it took 20 days for the pond to be fully covered, then it took 19 days for the pond to be half-covered, as the growth rate is exponential.

3. Answer: - It took 19 days for the pond to be half-covered with water lilies.

This calculation is based on the exponential growth of the water lilies in the pond.