Geoff planted dahlias in his garden. Dahlias have bulbs that divide and reproduce underground. In the first year, Geoff’s garden produced 4 bulbs. In the second year, it produced 8 bulbs, and in the third year, it produced 16 bulbs. If this pattern continues, how many bulbs should Geoff expect in the tenth year?

Following the pattern of doubling the number of bulbs each year, Geoff should expect 2^(10-1) = 2^9 = 512 bulbs in the tenth year.