An hourglass is turned over with the top part filled with
sand. after 3 minutes, there are 855 ml of sand in the top half. after 10
minutes, there are 750 ml of sand in the top half. This can be represents a two
points ( 3, 855) and (10, 750) . using this to solve the slope m =
(750-855)/(10-3) = -15. And using one point the equation is y = -15x + 900.
Answer: The answer is 8.
Step-by-step explanation: The first step is to convert the expression into figures. We shall call the unknown number Y. So if we are told “the square of a number,” that means Y squared, or better still, Y^2. Further we are told “the difference between the square of a number and 40” and that can be written as;
Y^2 - 40.
Next we are told that this expression is equal to 3 times that number (that is 3Y). That can now be written out as follows,
Y^2 - 40 = 3Y
If we move all expressions to one side of the equation, what we would have is,
Y^2 - 3Y -40 = 0
(Remember that when a positive value crosses to the other side of an equation it becomes negative and vice versa)
We now have a quadratic equation
Y^2 -3Y - 40 = 0
By factorizing we now have
(Y -8) (Y + 5) = 0
Therefore Y - 8 = 0 or
Y + 5 = 0
Hence, Y = 8 or Y = -5
Since we are asked to calculate the positive solution, Y = 8
Answer:
The answer is -0.7
Step-by-step explanation:
is the right answer
Answer:
Width is 10 1/2 inches and the length = 21 inches.
Step-by-step explanation:
Let the width be x then the length us 2x inches.
Perimeter = 2x + 2(2x) = 63
6x = 63
x = 10 1/2 inches.
Answer:
The probability that a radio selected at random will last from 600 to 700 hours is 0.3413
Step-by-step explanation:
The playing life of a Sunshine radio is normally distributed
Mean =
Standard deviation =
We are supposed to find the probability that a radio selected at random will last from 600 to 700 hours i.e.P(600<x<700)
Formula:
At x = 600
Z=0
At x = 700
Z=1
Hence the probability that a radio selected at random will last from 600 to 700 hours is 0.3413
