The speed of the current in a river is 6 miles per hour
<em><u>Solution:</u></em>
Given that,
Speed of boat in still water = 20 miles per hour
Time taken = 3 hours
Distance downstream = 78 miles
To find: Speed of current
<em><u>If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then: </u></em>
Speed downstream = (u + v) km/hr
Speed upstream = (u - v) km/hr
<em><u>Therefore, speed downstream is given as:</u></em>
We know that,
Speed downstream = (u + v)
26 = 20 + v
v = 26 - 20
v = 6 miles per hour
Thus speed of the current in a river is 6 miles per hour
Answer:
The answers are the 2nd, 5th, and last answer choices. Source: I did this question before and I remember the answers.
IAnswerQuestionsBoi avatar
Your welcome if that helped
Step-by-step explanation:
The correct answer is 90 miles per hour
Explanation:
The first step to know how fast Emily needs to drive to get 10 minutes earlier is to determine the distance from her work to her home. This can be calculated by using the information provided (speed and time). The process is shown below:
speed = distance ÷ time
distance = speed x time
distance = 60 miles per hour x 0.5 (30 minutes represent 0.5 hours)
distance= 30 miles
Now, using the same formula let's calculate the speed for 20 minutes (30 minutes - 10 minutes earlier = 20 minutes)
speed = distance ÷ time
speed = 30 miles ÷ 0.333 (20 minutes represents 0.333 hours as 20 minutes is 1/3 of an hour)
speed= 90 miles per hour
