Each dandelion produces 300 seeds. 1/3rd of the seeds land in water and die. 1/6 of the starting number are eaten by insects. Half the remainder sprout and are immediately eaten. How many dandelions survive long enough to flower? Think carefully first, then make a decision:
First find the number of seeds that land in water: 300 seeds * 1 / 3 = 100 seeds. Then find the number of seeds that are eaten: 300 seeds * 1 / 6 = 50 seeds. Subtract the number of seeds that are destroyed to find the number that sprout: 300 seeds - 100 seeds - 50 seeds = 150 seeds. Then divide that number by 2 to find the number of sprouts that survive: 150 seeds / 2 = 75 seeds. So, the answer is 75.