单选题
If Tom traveled 45 miles in 12 hours and Jim traveled four times as far in one-third the time, what was Jim"s average speed, in miles per hour?
【正确答案】
D
【答案解析】You are given that Tom traveled 45 miles in 12 hours and that Jim traveled four times as far in one-third the time. That means that Jim traveled 45x4, or 180 miles in 
, or 4 hours. Therefore, Jim traveled 
, or 4 hours. Therefore, Jim traveled