There are 40 counters in a bag. 13 are red, 20% are green and the rest are yellow. What proportion of counters are yellow?

20% green counters - means 1/5 of all counters are green. 1/5 of 40 = 40/5 = 8 counters are greenthe number of counters that are green + the number of counters that are red = 8 + 13 = 21the number of counters that are yellow = 40 - 21 = 19the proportion of counters that are yellow = 19/40 (simplest form as cannot be simplified)