Question

You spin the spinner twice.5678What is the probability of landing on an even number and then landing on a number less than 7?Write your answer as a percentage.

Answer 1

We have a spinner with four places: 5, 6, 7 and 8.

We have to calculate the probability of landing an even number and then landing on a number that is less than 7.

Both events are independent so we can write:

$P(E\&<7)=P(E)\cdot P(<7)$

We can then calculate each probability independently.

The probability of getting an even number is the quotient between the number successful outcomes (2 outcomes: getting a 6 and getting an 8) and the number of possible outcomes) (4 outcomes):

$P(E)=\frac{2}{4}=\frac{1}{2}$

The probability of getting a number that is less than 7 is 2/4 as we have 2 outcomes that are less than 7 (5 and 6) out of 4 possible outcomes.

Then, the probability is:

$P(<7)=\frac{2}{4}=\frac{1}{2}$

Then, the probability of both events together is:

$P(E\&<7)=P(E)\cdot P(<7)=\frac{1}{2}\cdot\frac{1}{2}=\frac{1}{4}=0.25$

We can express this probability as a percentage by multiplying it by 100%:

$P(E\&<7)=0.25\cdot100\%=25\%$

Answer: 25%