-- The trains start moving at the same time.
-- The space between them is initially 252.5 miles.
-- They reduce the distance between them at the rate of (124.7+253.5)=378.2mph.
-- It will take them (252.5 / 378.2) = 0.6676 hour to meet.
That's 40min 3.49sec .
-- After tooting and puffing toward each other for 8 minutes, they still have <em>32min 3.49sec</em> to go before they meet each other. We're all hoping that they're on different tracks.
Question 9. d
Question 10. b
Question 11.b
The answer would be 620000
Z score = (x -mean) / standard deviation.
For this problem X = 50 cm.
Z-score = (50 - 49.2) / 1.8
Z score = 0.8 / 1.8
Z score = 0.44
Look up 0.44 on a z-score table.
0.44 = 0.6700
0.67 x 100 = 67% will be 50 cm or longer.
Your answer is D. All of these statements are true.