The math required is not beyond the most elementary education, but the majority of people—even students at Ivy League colleges—only answer between one and two of the three questions correctly.23 That’s because they are designed with misleadingly obvious, but incorrect, answers (in this case, $0.10, 24 days, and 100 minutes). It is only once you challenge those assumptions that you can then come to the correct answer ($0.05, 47 days, and 5 minutes).
Math
