Question

The time it takes me to wash the dishes is uniformly distributed between 7 minutes and 15 minutes.

What is the probability that washing dishes tonight will take me between 13 and 14 minutes?
Give your answer accurate to two decimal places.

Answer 1

Hi :)

. Mathematically speaking, there are nine different times your dish-washing could take you. It could take you 7, 8, 9, 10, 11, 12, 13, 14 or 15 minutes.

And the probability for it to take you, say, 10 minutes, is equal to every other probability. This is, therefore, a situation of equiprobability.

100 / 9 = about 11,11111…
Meaning that each of the different outcome (be it for it to take 7, 8, 9, 10, 11, 12, 13, 14 or 15 minutes) has a 11,1111… probability to occur.

However, we are interested in two specific outcomes if our situation: we are interested in the dish-washing taking us 13 or 14 minutes.

2 x 11,1111 = roughly 22, 22 % probability, or 0,22 of probability.

I hope this helps! Have a nice day :)