simple probability

  Ana has 3 candies, 5 chocolates and 2 chewing gums in a bag. What is the probability of picking a candy?

Answer explanation

TOTAL POSSIBLE OUTCOMES: 10

NO. OF EVENTS: 3

PROBABILITY: 3/10

A number cube with faces numbered 1, 2, 3, 4, 5, 6 is rolled. Find the probability of obtaining a number greater than 4.

Answer explanation

The numbers greater than 4 are 5 and 6 only.

So, the number of event is 2 and the total possible outcome is 6.

Probability = 2/6 = 1/3

What is the probability of drawing a ball that is not red if a bag has 4 red balls, 5 blue balls, and 10 green balls?

Answer explanation

"Not a red ball" means any balls aside from red and those are blue and green.

blue= 5, and green=10

no. of favorable outcomes= 5+10=15

no. of all possible outcome: 4+5+10=19

so,

Probability (not a red ball) = 15/19

There are 20 sweets in a box. The probability that a chocolate is picked at random from the box is ½ or 50%. How many chocolates are in the box?

Answer explanation

The chocolate has a probability of 1/2, which means that

20/2 = 10 chocolates

Sabrinah has 12 cards, each with a shape on it. She takes a card at random. If the probability of drawing a card with the shape of a star is ¼, how many cards have the shape of a star?

Answer explanation

1/3 of 12 is 4.

This means that there are 4 cards has a shape of a star.

There are 18 pens in a bag. If the probability of getting a black pen is 2/3, how many black pens are there?

Answer explanation

2/3 of 18 is 12.