Step: 1

Number of students in the class is 40. So, the number of possible outcomes is 40.

Step: 2

Since all the students in the class are boys, number of favorable outcomes is 40.

Step: 3

Probability(event) = N u m b e r o f f a v o r a b l e o u t c o m e s N u m b e r o f p o s s i b l e o u t c o m e s .

[Formula]

Step: 4

P(boy) = 40 40 = 1

[Substitute the values.]

Step: 5

The probability that the student chosen is a boy is 1.

Correct Answer is : 1

Step: 1

Total number of possible outcomes is 52.

Step: 2

Number of favorable outcomes is 4.

Step: 3

Probability(event) = N u m b e r o f f a v o r a b l e o u t c o m e s N u m b e r o f p o s s i b l e o u t c o m e s

[Formula.]

Step: 4

P(a Jack) = 4 52 = 1 13

[Substitute the values and simplify.]

Step: 5

The probability that the card chosen is a Jack is 1 13 .

Correct Answer is : 1 13

Step: 1

Number of purple marbles in the jar is 13. So, the number of possible outcomes is 13.

Step: 2

Since, all the marbles in the jar are purple, the number of favorable outcomes is 13.

Step: 3

Probability(event) = N u m b e r o f f a v o r a b l e o u t c o m e s N u m b e r o f p o s s i b l e o u t c o m e s

[Formula.]

Step: 4

P(purple) = 13 13 = 1

[Substitute the values and simplify.]

Step: 5

The probability that the marble chosen is purple is 1.

Correct Answer is : 1

Step: 1

Number of favorable outcomes = 4.

[Since there are 4 black balloons.]

Step: 2

Number of possible outcomes = 8 + 4 = 12.

[Add the number of brown balloons and the number of black balloons.]

Step: 3

P(a black balloon) = N u m b e r o f f a v o r a b l e o u t c o m e s N u m b e r o f p o s s i b l e o u t c o m e s

Step: 4

= 4 12 = 1 3

[Substitute and simplify.]

Step: 5

The probability of selecting a black balloon is 1 3 .

Correct Answer is : 1 3

Step: 1

Number of possible outcomes is 12.

[Count numbers 0 to 11.]

Step: 2

Number of favorable outcomes is 1.

Step: 3

Probability(event) = N u m b e r o f f a v o r a b l e o u t c o m e s N u m b e r o f p o s s i b l e o u t c o m e s

[Formula.]

Step: 4

P(6) = 1 12

[Substitute the values.]

Step: 5

Probability of drawing the card numbered 6 is 1 12 .

Correct Answer is : 1 12

Step: 1

There are 10 numbers from 1 to 10. So, the number of possible outcomes is 10.

Step: 2

Number of favorable outcomes is 5.

[The even numbers are 2, 4, 6, 8 and 10.]

Step: 3

[Formula.]

Step: 4

P(even number) = 5 10

[Substitute the values.]

Step: 5

= 1 2

[Simplify.]

Step: 6

Probability of selecting an even number from the set of numbers from 1 to 10 is 1 2 .

Correct Answer is : 1 2

Step: 1

Total number of possible outcomes is 4.

Step: 2

Number of favorable outcomes = 3.

[There are 3 digits which are the multiples of 2.]

Step: 3

[Formula.]

Step: 4

P(digit which is a multiple of 2) = 3 4

[Substitute the values.]

Step: 5

Probability of selecting a digit, which is a multiple of 2, from the numbers 2, 7, 4 and 8 is 3 4 .

Correct Answer is : 3 4

Step: 1

Number of violet balls is 5. So, the number of possible outcomes is 5.

Step: 2

Since all the balls are violet, the number of favorable outcomes is 5.

Step: 3

Probability(event) = N u m b e r o f f a v o r a b l e o u t c o m e s N u m b e r o f p o s s i b l e o u t c o m e s .

[Formula]

Step: 4

P(violet ball) = 5 5

[Substitute the values.]

Step: 5

= 1

[Divide]

Step: 6

The probability of getting violet ball is 1.

Correct Answer is : 1

Step: 1

Total number of ice creams is 5. So, the number of possible outcomes is 5.

Step: 2

Number of cone ice creams that Emily chose is 1. So, the number of favorable outcomes is 1.

Step: 3

The probability of Emily choosing one cone ice cream = n u m b e r o f c o n e i c e c r e a m s t o b e c h o s e n t o t a l n u m b e r o f c o n e i c e c r e a m s .

Step: 4

= 1 5

[Substitute the values.]

Step: 5

So, the probability of Emily choosing one cone ice cream is 1 5 .

Correct Answer is : 1 5

Step: 1

There are 15 possible outcomes.

Step: 2

There are only 3 burgundy balls.

Step: 3

So, the probability of picking a burgundy ball is 3 15 = 1 5 .

Correct Answer is : 1 5

Step: 1

There are 52 possible outcomes.

Step: 2

There are 26 black cards in a deck of 52 cards.

Step: 3

So, the probability of selecting a card from the black suit is 26 52 = 1 2 .

Correct Answer is : 1 2

Step: 1

There are 19 possible outcomes.

Step: 2

There are only 6 mathematics books.

Step: 3

So, the probability of picking a mathematics book is 6 19 .

Correct Answer is : 6 19

Step: 1

There are 9 possible outcomes.

[There are 9 letters in the word.]

Step: 2

There is 1 'A' letter.

Step: 3

So, the probability of selecting A from the word SITUATION is 1 9 .

Correct Answer is : 1 9

- Possible Outcomes-Gr 7-Solved Examples
- Identifying Equally Likely Outcomes-Gr 7-Solved Examples
- Likelihood of an Event-Gr 7-Solved Examples
- Probabilities of Compound Events-Gr 7-Solved Examples
- Making Predictions-Gr 7-Solved Examples
- Making Inferences from Data of Two Populations-Gr 7-Solved Examples

- Probability