Step by step
The question
Question: The pattern red, white, white, blue, red, white, white, blue, ...
keeps repeating.
What is the 48th color?
1 Find the block
The list starts again after blue.
So the block that repeats is red, white, white, blue.
The block is 4 long.
2 Divide
The block comes again and again.
So we divide by its length.
What is left over tells us the place in the block.
4 times 12 is 48.
So 12 full blocks take us to the 48th color.
48 minus 48 is 0 more.
3 Count into the block
Nothing is left over.
So the 48th is the end of a block: the last one, blue.
4 Check
Let's check by counting on.
A block ends at the 44th color.
Then we count on: red, white, white, blue.
The 48th is blue.
So it is right!
Let's look back.
First: find the block.
Then: divide.
Then: count into the block.
Last: check.