Answer:
A}
Step-by-step explanation:
It is 10 times because it is one digit to the left that makes 10 times greater
Answer:
4 Hours
Step-by-step explanation:
Let's say that the rate of the machines 1/x, because every time they complete an order, it takes them x hours. To find x, we have to add the the rates of the individual machines, which would equal the rate of the machines working together. We know that there are four machines working together at the same rate, and it took them 32 hours.
So:
1/x + 1/x + 1/x + 1/x = 1/32
1/4x = 1/32
4x = 32
x = 8
Thus, the rate of the machines is 1/8.
Now we have to find the time of the order with only half of the machines working together. This time, we don't know the combined rate, so I'll substitute it for y.
1/8 + 1/8 = 1/y
1/4 = 1/y
y = 4
The time taken to complete it is 4 hours.
For this problem, you know that the first walker will arrive 2 hours before the second, and increases his speed by 2 times the second walker. You also know there is a distance of 24 km. So up until some time x, the two walkers have to be going the same speed. If the first walker increases speed by two times the speed per hour, and arrives two hours earlier, then his initial speed will be 20 km/h, because after 2 hours, he will have an increase of 4 km/hr, and the second will have an increase of 2 km/h, thereby making the first arrive 2 hours earlier, if that makes sense.
