Count how many balls are blue or even-numbered.
Count the total balls in the containers.
RED 1 2 3 4 5 6 7 8 9 ---------- 4 are even.
BLUE 1 2 3 4 5 6 7 ------------ 7 are blue.
Total ball count: 9+7=16.
--------the probability of one-time drawing either even or blue.