In a class activity, all the 15 students wear hats. 7 students wear red hats, 6 students wear green hats and 2 students wear white hats. Two of the 15 students are picked at random. Show that the probability that these two students wear hats of the same colour is $$$\frac{37}{105}$$$.

Mathematics

IGCSE&ALevel

CAIE

Exam No：0580_m21_qp_42 Year：2021 Question No：4(b)(ii)

Answer:

$\frac{7}{15} \times \frac{6}{14}+\frac{6}{15} \times \frac{5}{14}+\frac{2}{15} \times \frac{1}{14}$
$=\frac{37}{105}$

Knowledge points:

E8.5 Calculate the probability of simple combined events, using possibility diagrams, tree diagrams and Venn diagrams. (In possibility diagrams, outcomes will be represented by points on a grid, and in tree diagrams, outcomes will be written at the end of branches and probabilities by the side of the branches.)

Solution:

Download APP for more features

1. Tons of answers.

2. Smarter Al tools enhance your learning journey.

IOS
Download

Android
Download

Google Play
Download

In a class activity, all the 15 students wear hats. 7 students wear red hats, 6 students wear green hats and 2 students wear white hats. Two of the 15 students are picked at random. Show that the probability that these two students wear hats of the same colour is $$\(\frac{37}{105}\)$$.

Answer:

Knowledge points:

Solution:

Related Question