Unit 1 · Patterns and Sequences
Growing Bead Pattern — Find the 30th Bead Colour
Lesson 2 of 7
Repeating and growing patterns on Selective MR often ask for the 30th or 100th item — never count one-by-one when you can find which block it lands in.
Bead- and object-pattern questions appear regularly in the easy band of Selective MR — students who spot how group sizes grow save time and avoid miscounts.
The examiner checks whether you can partition the pattern into labelled groups, track cumulative counts, and identify which group contains the target position.
A visual pattern alternates colours with group sizes 1, 2, 3, 4, … (or a fixed cycle repeats). You find the colour or symbol at a large index such as the 30th bead.
Best approach: List group number, colour, size, and running total until the total reaches or passes the target. The answer is the colour of the group that contains that position.
Question
What colour is the 30th bead in the pattern below?
● ○ ○ ● ● ● ○ ○ ○ ○ ● ● ● ● ● ○ ○ ○ ○ ○ ○ …
(● = grey bead, ○ = white bead)
Select an answer to see the explanation.
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