Question

about how many times has mercury been around the sun in the time it has taken earth to go around ten times?
a once
b 2.5-times
c 4-times
d 40-times

Explanation:

Step1: Recall orbital periods

Earth's orbital period (time to go around Sun) is about 1 year. Mercury's orbital period is about 0.24 years (since it's faster).

Step2: Calculate time for Earth to go 10 times

Time for Earth to orbit 10 times: $10\times1 = 10$ years.

Step3: Calculate Mercury's orbits in 10 years

Number of Mercury's orbits = $\frac{10}{0.24}\approx41.67$, but wait, maybe a better way: Mercury's period is ~88 days, Earth's is ~365 days. 10 Earth years = 10×365 = 3650 days. Mercury's orbits: $\frac{3650}{88}\approx41.48$. Wait, but the options have 40 as d. Wait, maybe the approximate value: Mercury's period is ~0.25 years (simplified). So in 10 years, number of orbits: $\frac{10}{0.25}=40$. So the closest is d. Wait, but let's check again. Wait, maybe I made a mistake. Wait, Mercury's orbital period is about 88 days, Earth's is 365 days. So in one Earth year (365 days), Mercury orbits $\frac{365}{88}\approx4.15$ times. So in 10 Earth years, it's $10\times4.15\approx41.5$, which is closest to 40 (option d) or maybe the question uses approximate values. Wait, maybe the intended calculation: Mercury's period is 0.24 years, so 1/0.24 ≈4.17 per Earth year, times 10 is ~41.7, so 40 is the closest option (d).

Answer:

d. 40-times