Let x be the speed of the motorboat and y be the speed of the current.
Then, for downstream, the speed is x + y.
Now, speed = distance/time.
Distance = 80 miles.
Time for downstream = 4 hours.
So, x + y = 80/4 = 20 (1)
Against the current, that is for upstream, the speed is x - y.
Time for upstream = 5 hours.
x - y = 80/5 = 16 (2)
Adding (1) and (2), we get,
2x = 36
x = 18
Hence, rate of the motorboat in calm water = 18 miles/hour.
Answer:
It could be
Step-by-step explanation:
The calculation of sides of a rectangular triangle can be done by applying the Pythagorean theorem (the sum of the squares of the legs is equal to the square of the hypotenuse), both legs must form a right angle, and the value of the hypotenuse must be different from the legs. In the example what you give could be a value of one leg and the other of the hypotenuse.
Answer:
y^2 + 4y + 3
Step-by-step explanation:
(y + 3)(y + 1)
(y*y) + (y*1) + (3*y) + (3*1)
y^2 + y + 3y + 3
y^2 + 4y + 3
Best of Luck!
Answer:
11.75 = 5.25 + x
x = 6.50
Step-by-step explanation:
Lan is 146 centimeters tall now.
<u><em>Explanation</em></u>
Let, Lan's current height is 
centimeters
As Lisa is 6 centimeters taller than Lan and Lan is 10 centimeters taller than Jim, so Lisa's current height = 
centimeters and Jim's current height = 
centimeters.
Every month, their heights increase by 2 centimeters.
So, after 5 months.....
Lan's height = 
centimeters,
Lisa's height = 
centimeters and
Jim's height = 
centimeters
Given that, the sum of Ian's and Jim's heights will be 140 centimeters more than Lisa's height in 5 months. So the equation will be....
So, the current height of Lan is 146 centimeters.
