Question

костя провел под водой 900 секунд.Половину всего этого времени он рассматривал камбалу,1/5 часть всего времени гнался за стаей скумбрий,а остальное время - наблюдал за черноморской акулой.Сколько времени он наблюдал за черноморской акулой?

Answer 1

1)900\2=450-рассматривал камбалу

2) гнался за стаей скумбрией 900\5=180

3)450+180=630 рассматривал камбалу и гнался за стайкой скумбрией

4)900-630=270 наблюдал за черномордой акулой

Answer 2

Условия:

всего - 900

камбала - $\frac{1}{2}$ всего времени

скумбрии -  $\frac{1}{5}$ всего времени

акула -оставшееся, ?

 

Решение:

1) 900 · 1/2 = 450 сек (камбала)

2) 900 · 1/5 = 180 сек (скумбрии)

3) 900 - (450 + 180) = 270 сек (акула)

Ответ: 270 секунд наблюдал за черноморской акулой

Answer 3

Calculation of Time Spent Observing the Black Sea Shark

To determine how much time Kostya spent observing the Black Sea shark, we need to calculate the time spent on each activity and then subtract that from the total time spent underwater.

Given the information provided, we know that Kostya spent a total of 900 seconds underwater. Let's break down the time spent on each activity:

- Time spent observing the flounder: Kostya spent half of the total time underwater observing the flounder. Since half of 900 seconds is 450 seconds, he spent 450 seconds observing the flounder.

- Time spent chasing the mackerel: Kostya spent 1/5 (or 1 out of 5) of the total time underwater chasing the mackerel. To calculate this, we divide 900 seconds by 5, which gives us 180 seconds. Therefore, he spent 180 seconds chasing the mackerel.

Now, let's calculate the time spent observing the Black Sea shark:

- Total time spent observing the Black Sea shark: To find this, we need to subtract the time spent observing the flounder and chasing the mackerel from the total time spent underwater.

Total time spent observing the Black Sea shark = Total time underwater - Time spent observing the flounder - Time spent chasing the mackerel

Total time spent observing the Black Sea shark = 900 seconds - 450 seconds - 180 seconds

Total time spent observing the Black Sea shark = 270 seconds

Therefore, Kostya spent 270 seconds observing the Black Sea shark.