Answer:
Step-by-step explanation:
a) sum of angle on the straight line TRW is 180.
Given <TRS = 2x+10
<SRW = x-10
<TRS+<SRW = 180
2x+10+x-10 = 180
3x = 180
x = 180/3
x = 60°
<TRV = 180°-(2x+10)
Substitute x = 60° into the expression
<TRV = 180-(2(60)+10)
<TRV = 180-(120+10)
<TRV = 180-130
<TRV = 50°
2) From the diagram attached <MHJ= <LHK (oppositely directed angle)
Given
<MHJ= x+15
<LHK = 2x-20
Substitute the given data into the formula to get x
x+15= 2x-20
x-2x = -15-20
-x = -35
x = 35°
Next is to get the measure of <MHJ
<MHJ = x+15
<MHJ = 35+15
<MHJ = 50°
Let x represent number of redwood trees and y represent number of spruce trees.
We have been given that a park ranger bought 12 trees. We can represent this information in an equation as:


We are also told that redwood trees cost $24 each, so cost of x redwood trees would be
.
Each spruce tree costs $16, so cost of y spruce trees would be
.
Since the park ranger spent $208 on trees, so we can represent this information in an equation as:

Upon substituting equation (1) in equation (2), we will get:







Therefore, the park ranger bought 2 redwood trees.
Upon substituting
in equation (1), we will get:

Therefore, the park ranger bought 10 spruce trees.
Mean = 450 sec
standard deviation = 50 sec
450-50 =400
450+50=500
Between 400 sec and 500 sec means one deviation above and one deviation below the mean, and it is 68%.
68%=0.68
0.68*288= 195.84≈196
Answer is d) 196