Question

6. Отец может выкопать всю картошку на огороде за 9 часов, а сын – в 3 раза быстрее. За сколько часов они выкопают 2/3 картошки, если будут работать вместе?

Answer 1

9*3=27
27:2=13,5
13*3=39
Ответ:за 39 они выступают 2/3 картошки если будут работать вместе.

Answer 2

Problem Analysis

We are given that the father can dig up the entire potato field in 9 hours, while the son is three times faster. We need to determine how many hours it will take for them to dig up 2/3 of the potatoes if they work together.

Solution

Let's start by finding the son's digging speed. Since the son is three times faster than the father, his digging speed is 1/3 of the father's speed.

Next, we need to calculate the combined digging speed of the father and son when they work together. To do this, we add their individual digging speeds.

Once we have the combined digging speed, we can calculate the time it will take to dig up 2/3 of the potatoes by dividing 2/3 by the combined digging speed.

Let's calculate the solution step by step.

Step 1: Calculate the son's digging speed

The son's digging speed is 1/3 of the father's speed.

Son's digging speed = (1/3) * Father's digging speed

Step 2: Calculate the combined digging speed

The combined digging speed is the sum of the father's and son's digging speeds.

Combined digging speed = Father's digging speed + Son's digging speed

Step 3: Calculate the time to dig up 2/3 of the potatoes

The time to dig up 2/3 of the potatoes is calculated by dividing 2/3 by the combined digging speed.

Time to dig up 2/3 of the potatoes = (2/3) / Combined digging speed

Let's calculate the solution using the given information.

Solution Calculation

Given: Father's digging speed = 1 (the entire field in 9 hours) Son's digging speed = 1/3 (since the son is three times faster than the father)

Step 1: Calculate the son's digging speed Son's digging speed = (1/3) * 1 = 1/3

Step 2: Calculate the combined digging speed Combined digging speed = 1 + 1/3 = 4/3

Step 3: Calculate the time to dig up 2/3 of the potatoes Time to dig up 2/3 of the potatoes = (2/3) / (4/3) = (2/3) * (3/4) = 1/2

Answer

If the father and son work together, they will be able to dig up 2/3 of the potatoes in 1/2 hour.