Maths Bond 9-10 test 16

[Tulip]

Please could anyone help me on this question?

Bond maths 9-10 test 16 Q-5

There are 13 beads. The first bead is white,the 2nd and 3rd are black,4th and 5th are white and the 6th is black,7th is white, 8th and 9th are black, the 10th and 11th are white, the 12th is black and the 13th is white.

Question is - Look at this line of beads. What colour will the 19th bead be ?

[Ladymuck]

It is a repeating sequence:

WBBWWB WBBWWB W

So the 19th bead will be White.

[Tulip]

Thanks Ladymuck, now i understood and i didn't think of the sequence!