Suppose a bag of marbles has 4 green, 2 red, 5 yellow, 1 brown, and 7 blue marbles. what is the probability of picking a green marble?

The bag of marbles has 4 green, 2 red, 5 yellow, 1 brown, and 7 blue marbles.

Total number of marble=4+2+5+1+7=19

The probability P(E) is defined as

where n(E) is the total number of favourable events.

and n(s) is the total number of events

Hence for the given data we can write

Because total number of green marbles = n(E)=4

Total number of Marbles =n(S)=19

Hence P(E)=4/19