 
 <translate> Answer = C. 110 miles
Relational speed = 120 - 100 = 20 miles per hour
In 4 hours, difference = 20 * 4 = 120 miles
Fast train trailing 10 miles, so effective difference = 120 - 10 = 110 miles
Therefore, the answer is (C). <ibo> Azịza = C. 110 kilomita Relational ọsọ = 120 - 100 = 20 kilomita kwa awa N'ime awa anọ, ọdịiche = 20 * 4 = 120 kilomita Ụgbọ oloko na-agba ọsọ ọsọ na-agbada kilomita iri, ya mere ọdịiche dị irè = 120 - 10 = kilomita 110 N'ihi ya, azịza ya bụ (C). 