Answer: the rate of speed for train A is 66 miles per hour.
Step-by-step explanation:
Let x represent the speed of train B.
2 trains leave the station at the same time. Train A is traveling 16 miles per hour slower than train B. This means that the speed of train A would be x - 16 miles per hour.
The two trains are 720 miles apart after 4 hours. It means that both trains traveled a total distance of 720 miles in 4 hours.
Distance = speed × time
Distance travelled by train A after 4 hours is
4(x - 16) = 4x - 64
Distance travelled by train B after 4 hours is
4 × x = 4x
Since the total distance travelled by both trains is 720 miles, then
4x - 64 + 4x = 720
8x = 720 - 64 = 656
x = 656/8 = 82 miles per hour
The speed of train A would be
82 - 16 = 66 miles per hour.
Speed = distance / time
speed = 135/3 = 45 miles per hr <==
Answer:
1/6
Step-by-step explanation:
Ok, so the quadratic coefient is 1, so great
take 1/2 of the linear coefient and square it
10/2=5, (5)^2=25
add that to both sides
x^2+10x+25=7+25
factor perfect square trionomial
(x+5)^2=32
squaer root both sides
x+5=+/-4√2
minus 5
x=-5+/-4√2
x=-5+4√2 and -5-4√2
Answer:
0.205 ; 0.117 ; 0.999
Step-by-step explanation:
Using binomial probability distribution :
P(x =x) = nCx * p^x * (1 - p)^(n - x)
Probability of success, p = 0.5
P(x = 4) = 10C4 * 0.5^4 * 0.5^6
P(X = 4) = 0.205078125
B.) 3 heads and 7 tails
P(X = 7) = 10C7 * 0.5^7 * 0.5^3
P(X = 7) = 120 * 0.0009765625
P(X = 7) = 0.117
P(atleast one head)
P(x greater than equal to 1) = p(x =1) +... P(x = 10)
Using a binomial probability calculator :
P(x greater than equal to 1) = 0.999
