High School

In a factory, a machine produces 100 items in one hour. Answer the following questions. Assume that the machines work at the same tempo.

1. How many machines will you need to produce 500 items per hour?

2. How long will it take 4 machines to produce 100 items?

3. How many items do 8 machines produce in 45 minutes?

4. If a rescue vessel has enough provisions for 10 people to survive for 6 days, how long will 12 people survive on the vessel?

5. A motorist takes 4.5 hours to reach his destination at 80 km/h.

a. If he wants to complete his journey in 4 hours, at what speed must he travel?

b. If he drives at 110 km/h, how long will the journey be? Give the answer in hours and minutes.

Answer :

Sure! Let's break down each of the questions step by step:

1. How many machines will you need to produce 500 items per hour?
- Each machine produces 100 items in one hour.
- To produce 500 items in one hour, you need several machines.
- Divide the target number of items (500) by the number of items one machine produces (100).
- [tex]\( \text{Number of machines needed} = \frac{500}{100} = 5 \)[/tex].
- So, you need 5 machines.

2. How long will it take 4 machines to produce 100 items?
- Each machine produces 100 items in one hour.
- Four machines combined produce [tex]\( 4 \times 100 = 400 \)[/tex] items in one hour.
- You need to produce 100 items.
- Divide the target number of items (100) by the total number of items produced by 4 machines in one hour (400).
- [tex]\( \text{Time required in hours} = \frac{100}{400} = 0.25 \)[/tex].
- So, it will take 0.25 hours, which is 15 minutes.

3. How many items do 8 machines produce in 45 minutes?
- Each machine produces 100 items in one hour.
- Eight machines produce [tex]\( 8 \times 100 = 800 \)[/tex] items in one hour.
- Convert 45 minutes to hours [tex]\( \text{(45 minutes)} = \frac{45}{60} \)[/tex] hours = 0.75 hours.
- Multiply the number of items produced by 8 machines in one hour by 0.75.
- [tex]\( \text{Items produced} = 800 \times 0.75 = 600 \)[/tex].
- So, 8 machines produce 600 items in 45 minutes.

4. How long will 12 people survive on the vessel?
- Provisions last 6 days for 10 people.
- Calculate the total provisions available: [tex]\( 10 \times 6 = 60 \)[/tex] person-days.
- For 12 people, divide the total person-days by the number of people.
- [tex]\( \text{Days for 12 people} = \frac{60}{12} = 5 \)[/tex].
- So, 12 people will survive for 5 days.

5. If he wants to complete his journey in 4 hours, at what speed must he travel?
- Current travel time is 4.5 hours at 80 km/h.
- Calculate the total distance [tex]\( \text{Distance} = 80 \times 4.5 = 360 \)[/tex] km.
- He wants to cover this distance in 4 hours.
- Divide the distance by the time to find the speed.
- [tex]\( \text{Required speed} = \frac{360}{4} = 90 \)[/tex] km/h.
- So, he must travel at 90 km/h.

6. If he drives at 110 km/h, how long will the journey be? Give the answer in hours and minutes.
- Use the same distance: 360 km.
- Divide the distance by the new speed.
- [tex]\( \text{Time for journey} = \frac{360}{110} \approx 3.27 \)[/tex] hours.
- Convert 0.27 hours to minutes: [tex]\( 0.27 \times 60 \approx 16 \)[/tex] minutes.
- So, the journey will take 3 hours and 16 minutes.

I hope this clarifies the problem! Let me know if you have any more questions.