Question

5. A six-marble repeating pattern made up of

ebloured marbles is shown.
How many times does a red marble appear
in the first 20 marbles of this pattern?
Explain your answer.

Answer 1

7 marbles

Explanation:

For every 6 marbles, 2 marbles appear as red.

This pattern would repeat thrice as 6x3 = 18, and then the first 2 marbles (one blue and red) will be counted to make 20 marbles.

So total marbles will be 3x2 in the 18 marble set and 1 in the final 2 marbles.

so 3x2 + 1 = 6+1 = 7

We get 7 marbles as red if we continue in this pattern.