The speed of a boat in still water is 40 mph. If it takes the same time for the boat to travel 8 miles upstream as it does to travel 24 miles downstream, then what is the speed of the current?

Current speed is 40mph

Step-by-step explanation:

We firstly need to know what is intended by upstream and downstream. When the boat travels in the direction of the current (horizontal movement of the water), we say it is moving downstream otherwise it is moving upstream.

Let's assume the speed of the boat is A and that of the current is B, then the speed when it moves dowstream would be A + B and the speed if it moves upstream would be A – B.

In this question, we know that the speed of the boat is 40mph. Given that it takes the same time to travel 8miles upstream as it does to travel 24miles downstream, we have

Speed upstream = 8/t

Speed downstream = 24/t

Respectively.

Let speed of current be X, then

Speed downstream = 40 + X

Speed upstream = 40 – X

From the question we have:

(40 + x)/24 = (40 – X)/8

(40 + x)/3 = (40 – x)/1

3(40 – x) = 40 + X

120 – 3x = 40 – X

120 – 40 = 3x – X

2x = 80

X = 40.

Therefore, current speed is 40mph

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.

y=3n + 1

step-by-step explanation:

this is wrong because it says the second number is one less and i added one instead