Answer:
85
Step-by-step explanation:
Write the numbers in order
66, 72, 74, 80, 83, 87, 91, 95, 98, 99
Find the middle number
83 and 87 are in the middle, so find the mean of them. 83+87= 170
170/2 = 85.
Answer:
The sidewalk moves at 0.5 ft/sec
Josie's speed walking on a non-moving ground is 3.5ft/sec
Step-by-step explanation:
Let x represent the speed of the side walk and y represent her walking speed
It takes Jason's 8-year-old daughter Josie 44 sec to travel 176 ft walking with the sidewalk
Distance = speed × time
176 = (x+y)×44
44x+44y = 176
x+y = 4 .......1
It takes her 7 sec to walk 21 ft against the moving sidewalk in the opposite direction).
21 = (y-x)7
7y - 7x = 21
y - x = 3 ......2
Add equation 1 to 2
2y = 7
y = 3.5 ft/sec
From equation 1
x + y = 4
x = 4 - 3.5 = 0.5
x = 0.5 ft/sec
The sidewalk moves at 0.5 ft/sec
Josie's speed walking on a non-moving ground is 3.5ft/sec
In an arithmetic sequence:
Tn=t₁+(n-1)d
t₄=t₁+(4-1)d=t₁+3d
t₅=t₁+(5-1)d=t₁+4d
t₆=t₁+(6-1)d=t₁+5d
t₄+t₅+t₆=(t₁+3d) +(t₁+4d)+(t₁+5d)=3t₁+12d
Therefore:
3t₁+12d=300 (1)
t₁₅=t₁+(15-1)d=t₁+14d
t₁₆=t₁+(16-1)d=t₁+15d
t₁₇=t₁+(17-1)d=t₁+16d
t₁₅+t₁₆+t₁₇=(t₁+14d)+(t₁+15d)+(t₁+16d)=3t₁+45d
Therefore:
3t₁+45d=201 (2)
With the equations (1) and (2) we make an system of equations:
3t₁+12d=300
3t₁+45d=201
we can solve this system of equations by reduction method.
3t₁+12d=300
-(3t₁+45d=201)
-----------------------------
-33d=99 ⇒d=99/-33=-3
3t₁+12d=300
3t₁+12(-3)=300
3t₁-36=300
3t₁=300+36
3t₁=336
t₁=336/3
t₁=112
Threfore:
Tn=112+(n-1)(-3)
Tn=112-3n+3
Tn=115-3n
Now, we calculate T₁₈:
T₁₈=115-3(18)=115-54=61
Answer: T₁₈=61
Answer:
Candace has $57.5 and Amar has $37.5.
Step-by-step explanation:
x+(x+20)=z
x+20=y
x+y=z
--------------
2x+20=95
2x=95-20
2x=75
x=75/2
x=37.5
37.5+20=y=57.5
