Let S = his average speed.
Let D = distance traveled one way
Time = distance / speed
Set up an equation:
d/6 + d/12 = 2d/S
Multiply the equation by 12s:
12s(d/6) + 12s(d/12) = 12s(2d/s)
Simplify to get:
2sd + sd = 24d
Combine like terms:
3sd = 24d
Divide both sides by d:
3s = 24
Divide both sides by 3:
s = 24/3
s = 8
His average speed was 8 mph.
Answer:
length = 20 cm
width = 9 cm
Step-by-step explanation:
perimeter = 58 cm
58cm = 2*L+2*w equation 1
L = 3w -7 equation 2
where:
L= length
w=width
so we have:
58 = 2(3w -7) +2w
58 = 6w -14 +2w
58 +14 = 8w
72 = 8w
w = 72/8
w = 9 cm = width
we have:
L = 3(9) -7 = 20 cm = length
Answer:
the standard deviation of the speeds of cars travelling on California freeways is 6.0 miles per hour
Step-by-step explanation:
The computation of the standard deviation of the speeds of cars is shown below;
The z score for the top 1% is 2.326
So,
= (75 - 61) ÷ standard deviation = 2.326
Standard deviation is
= 14 ÷ 2.326
= 6.0 miles per hour
Hence, the standard deviation of the speeds of cars travelling on California freeways is 6.0 miles per hour
Answer:
25/4
Step-by-step explanation:
Multiplying numerators gives 4950 and multiplying denominators gives 792. 4950/792. simplify to get simplest form as 25/4
