Question 744835
A car accelerates steadily so that it goes from a velocity of 20 m/s to a velocity of 40 m/s in 4 seconds. What is its acceleration? 
(40 - 20)/4 = 5 m/sec/sec
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2        The average of three numbers is 48. The average of two of these numbers is 56. What is the third number? 
3*48 = 144
2*56 = 112
----------- Subtract
3d num= 32