Answer:
1. 23/20 miles, 2. 7/20 miles
Step-by-step explanation:
1. Total distance = 3/4 + 2/5
= (3*5)/(4*5) + (2*4)/(5*4)
= 15/20 + 8/20
= 23/20
= 1 3/20 miles
2. Difference between walked miles and jogged miles = 3/4 - 2/5
= 15/20 - 8/20
= 7/20 miles
Answer:
Height: 3/2 inches
Length: 12 inches
Width: 4 inches
Step-by-step explanation:
Let x is the side length of the square
The height of the box by cutting squares off :x
- The new length of the cardboard = 15 -2x (because we cut from 4 corners)
- The new width of the cardboard = 7 -2x (because we cut from 4 corners)
The new volume of it is:
V = (15 -2x) (7 -2x) x
<=> V =
To maximum volume, we use the first derivative of the volume
<=> 
<=> 
<=> 2x -3 = 0 or 6x -35 = 0
<=> x = 3/2 or x = 35/6
To determine which value of x gives a maximum, we evaluate
= 24x -88
= 24(3/2) -88 = -52
= 24(35/6) -88 = 52
We choose x = 3/2 to have the maximum volume because the value of x that gives a negative value is maximum.
So the dimensions (in inches) of the box is:
Height: 3/2 inches
Length: 15-2(3/2) = 12 inches
Width: 7 - 2(3/2) = 4 inches
Answer:
Option D is the correct answer.
Step-by-step explanation:
Initial height = 4 feet
Given that the height of the tree increased by a constant amount each year for the next 6 years. At the end of the 6th year, the tree was 1/5th taller than it was at the end of the 4th year.
Let the rate of growing each year be g.
After 6 years height of tree = 4 + 6g
After 4 years height of tree = 4 + 4g
At the end of the 6th year, the tree was 1/5th taller than it was at the end of the 4th year.
That is

Option D is the correct answer.
Mean = (18 + 21 + 17 + 24 + 15) divided by 5
Mean = 95 divided by 5
Mean = 19