Answer:
300 miles
Step-by-step explanation:
Let us consider the miles they travelled is 'm'
Mileage for Primo= 21 + (m Ă— 0.20) = 21+0.2m
Mileage for Ultimo= 24+ ( mĂ— 1.00) = 24 + m
Question says The mileage is equal when Ultimo's charge is 4Ă— Primo
Thus,
4 Ă— (21+0.2m) = 24+ m
84 + 0.8m = 24 + m
60 = 0.2m
m = 300