Answer: the two trains will meet in 2.8 hours
Step-by-step explanation:
Step 1
Speed of train A = 90mph
Speed of train B = 110 mph
Since both trains are travelling towards each other
, their effective speed will be= 90 mph + 110mph= 200mph
Step 2
we know that Speed = distance / time
therefore Time = Distance / speed
Distance = 560 miles
Speed = 200 mph
Time = 560miles / 200mph
2.8 hours
The mean is the sum of all 12 numbers divided by 12, which is 578.25 ~ 578.3. The variance is calculated by subtracting each score from the mean, squaring, and adding all such squares. Then divide by the number of terms (12) to get 68572.35. Take the square root to get the standard deviation, which is 261.9. So the correct answer is B.
Her brother joe made $52.08. First you need to make the percent into a decimal, like this 86% => .86. Then multiply .86 to $28. After that add what you got to $28.