There are20 keys on a keychain. one of the keys starts a car. if a key is randomly chosen what is the probability that it starts the car

a)5% b)25% c)20% d)15%

answer: 21$

step-by-step explanation:

$42 / $14 = 3   (ratio 3: 1)

$7 x 3 = $21

cluster sampling.

step-by-step explanation:

the given 6 = w/p is equivalent to 6p = w, where w is the total area of the walls and p is the area covered by a single can of paint.

knowing that 6 cans of paint will be needed, 6p = w becomes 6(6) = w = 36.   this tells us that the total area to be painted is 36 square units.