<h3>
Answer: </h3><h3>
speed of train A = 44 mph</h3>
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Work Shown:
x = speed of train A
y = speed of train B
"train A travels 4/5 the speed of train B" (I'm assuming "train one" is supposed to read "train B"). So this means x = (4/5)y
distance = rate*time
d = x*7
d = (4/5)y*7 = (28/5)y represents the distance train A travels
d = y*7 = 7y represents the distance train B travels
summing those distances will give us 693
(28/5)y + 7y = 693
5*( (28/5)y + 7y ) = 5*693
28y + 35y = 3465
63y = 3465
y = 3465/63
y = 55
Train B's speed is 55 mph
4/5 of that is (4/5)y = (4/5)*55 = 4*11 = 44 mph
Train A's speed is 44 mph
The distance from your house to your grandparents house is
3.67 miles or 19377.6 ft.
So the total number of strides needed would be:
strides needed = 19377.6 ft / (2.6 ft / stride)
<span>strides needed = 7,452.92 = 7,453 strides</span>
The probability that none of the four have been vaccinated is
(1-0.63)^4 = 0.01874161
The probability that at least one has been vaccinated is the complement of this,
≈0.9813
X > -4 is the answer if you solve for x.
