Try this beautiful Problem based on Counting Principle from Math Kangaroo (Ecolier) 2017 Problem 22.
A small zoo has a giraffe, an elephant, a lion and a turtle. Susi wants to visit exactly two of the animals today but does not want to start with the lion. How many different possibilities does she have, to visit the two animals one after the other?
Pattern
Counting
Math Kangaroo (Ecolier) 2017 Problem 22
9
Try to organize the choices to make sure that you count each and every option only once.
Let us try to consider the case where she start to visit from Giraffe.
So then we can have 3 ways to visit i.e. Giraffe, Lion; Giraffe, Turtle; Giraffe, Elephant.
In this way try to find out all the other ways we can have for visiting the zoo.
Also we have to remember that we can't start with Lion.
Other ways are elephant, lion; elephant, turtle; elephant, giraffe and turtle, giraffe; turtle, elephant; turtle, lion.
So in total we can have 3+3+3= 9 ways.
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