Question

1) Швидкість човна 22 км/год , швидкість течії річки 2 ⅔ км/год. За який час катер подолає відстань 74 км? 2)За три дні зорали 144 га землі. Першого дня зорали 4/9, а другого 55% решти. Скільки гектарів землі зорали третього дня? Пожалуйста помогите это кр СРОЧНО МНЕ СКОРО НУЖНО ЗДАВАТЬ ПОМОГИТЕ(⁠༎ຶ⁠ ⁠෴⁠ ⁠༎ຶ⁠)ДАЮ 19 БАЛОВ

Answer 1

Problem 1: Speed of a Boat and River Current

To find the time it takes for a boat to travel a certain distance, we can use the formula:

Time = Distance / Speed

Given: - Boat speed = 22 km/h - River current speed = 2 ⅔ km/h - Distance to be covered = 74 km

To calculate the time it takes for the boat to cover the distance, we need to consider the effect of the river current. The boat's speed relative to the ground will be the difference between its speed and the current speed.

Let's calculate the time it takes for the boat to cover the distance:

Step 1: Calculate the effective speed of the boat relative to the ground.

The effective speed of the boat is the difference between the boat's speed and the river current speed:

Effective speed = Boat speed - River current speed

Effective speed = 22 km/h - 2 ⅔ km/h

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 3:

Effective speed = 22 km/h - (2 ⅔ km/h * 3/3)

Effective speed = 22 km/h - (8/3 km/h)

To subtract fractions, we need to have the same denominator:

Effective speed = (66/3 km/h) - (8/3 km/h)

Effective speed = (66 - 8)/3 km/h

Effective speed = 58/3 km/h

Step 2: Calculate the time it takes for the boat to cover the distance.

Now that we have the effective speed, we can use the formula:

Time = Distance / Effective speed

Time = 74 km / (58/3 km/h)

To divide by a fraction, we can multiply by its reciprocal:

Time = 74 km * (3 km/h / 58)

Time = (74 * 3) / 58 hours

Time ≈ 3.805 hours

Therefore, it will take approximately 3.805 hours for the boat to cover a distance of 74 km.

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