Since there are 2 black sixes and 2 black eights in a typical deck of 52 cards, the probability of choosing one of those 4 out of 52 is 4/52 or 1/13.
The answer is 27. because 9 times 3 =27 and 3 times 9 = 27. so they are both constant of proportionality.
A car travels 440km in 15.4 hours -> In 1 hour, the car travel 1/(15.4) the distance.
So in an hour, the car travel : 440 x 1/(15.4) = 28.5714285714... (round to 29)
So, the average speed of the car is approximately 29 km/h