Respuesta :
He has biked 70 miles out of the 100 miles, because of you multiply 7/10 by 10 so the denominator is 100 (100miles) you also have to multiply the numerator by 10 so 70, 70/100 miles!
total miles =100
miles covered = 7/10
this mean s/he has covered 100*7/10 = 7
miles covered = 7/10
this mean s/he has covered 100*7/10 = 7