For blue sticks, list down the multiples of 6. For red sticks, list down multiples of 7. But since it has a 8cm ‘headstart’, you need to add 8cm to every multiple. Then look for the number that matches, in this case, 36cm. Refer back to the table and look at the ‘Number of Sticks’ under the row of ‘Red Sticks’ which is 4.