Apart-time worker earned five times as much in september as in each of the other months. what part of the worker's earnings was earned in september?

Suppose that a worker earns x$ every other month. In September he earns 5x. We have that his total earnings are 11*x +5x (Eleven months income plus September). Hence 16x is the amount of total earnings. The ratio of earnings in September to the total earnings is =0.3125. Hence, 31,25% of his earnings where accrued in September.