There is a bag with only red marbles and blue marbles. The probability of randomly choosing a blue marble is 1/9 There are 45 marbles in total in the bag and each is equally likely to be chosen. Work out how many red marbles there must be.

40

Step-by-step explanation:

Since the probability to choose a blue marble is 1/9, there must be 5 blue marbles since 45 * 1/9 = 5

Subtract 5 from 45 to get 40, since the rest of the marbles are red.

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)