The question is in the description.

Question

There are cards in a box. Fifteen of these cards are red, the others are blue, and the rests are white cards. If the probability of drawing a blue card is 0.125 and the probability of drawing a white card is twice the probability of getting a blue card, how many cards are there in the box?

a. What is the probability of the red cards?

b. How many cards are there in the box?

c. How many white cards are in the box?

d. How many blue cards are in the box?

Answer 1

Each probability is the proportion of each color card in the total deck. Each of these calculations would be calculated as the number of a particular color/total cards. We don't know the total cards, but we do know the number of red cards. If we solve for the probability of a red card, we can use that information to solve for the total number of cards.

We do know the probability of blue, and by extension, white. One other property of probability is the sum of all probabilities for all possible outcomes =1

so p(blue) = .125

p(white) = .25

p(red) = 1 - (.25+.125) = .625

If there are 15 red cards, p(red) = #red/total cards

so .625= 15/total total = 15/.625 = 24 total cards.

for blue and white: Total (probability) = number of cards