Trina has two spinners. One spinner has 4 equal sections that are numbered 1 through 4. The other spinner has 5 equal sections that are numbered 1 through 5.

Trina spins both spinners at the same time.

The random variable X is the sum of the numbers on which the spinners land.

What is P(5≤X≤8)?


Enter your answer, in simplest fraction form, in the box.

adore.nuk  Feb 15, 2018

1+0 Answers


The answer is 13/20.

The easiest way is to write down all the possible totals eg 1from first spinner and 3 from the second gives a total of 4. There are 20 possible totals but some totals will occur more than once eg 7 occurs 3 ways ie 2,5 ; 3,4 and 4,3. Once you have all 20 it's then a matter of counting how many ways the totals of 5,6,7 and 8 occur.

Guest Feb 16, 2018

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