Probability Practice Test 1

Question : 24 of 40

Marks: +1, -0

A dice is rolled three times and the sum ofthree numbers appearing on the uppermostface is 15. The chance that the first roll was afour is:

$2/5$
$1/5$
$1/6$
None of these

Validate

Solution:

Possible outcomes are: (3, 6, 6) (6, 3, 6) (6, 6, 3) (5, 5, 5) (4, 5, 6) (4, 6, 5) (5, 6, 4) (5, 4, 6) (6, 5, 4) (6, 4, 5)
Number of favourable outcomes are: (4, 6, 5) (4, 5, 6)

P(E) ={\Number \of \total \outcomes}/{\Number \of \favourable \outcomes }

=2/10=1/5

Go to Question:

Prev Question

Next Question