If the train went 390 miles in 3 hours, what was the speed in miles per hour

Speed = 130 mph

Step-by-step explanation:

Distance travelled = 390 miles

Time taken = 3 hours

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐