Tracie and Marcia drove to Northern California to see Marcia’s sister Eureka. Tracie drove one hour more than four times as much as Marcia. The trip took a total of 21 driving hours. How many hours did Tracie drive?

Tracie drove for 17 hours.

Step-by-step explanation:

Given that,

Tracie and Marcia drove to Northern California to see Marcia’s sister Eureka.

Let us assume,

⇒ one hour more than four times of Marcia = 1+4x

The trip took a total of 21 driving hours.

To find the number of hours Marcia drove :

⇒ Tracie hours + Marcia hours = Total hours.

⇒ (1+4x) + x = 21

⇒ 1 + 5x = 21

⇒ 5x = 20

⇒ x = 20/5

⇒ x = 4

Therefore, Marcia drove for 4 hours.

To find the number of hours Tracie drove :

Substitute x=4, in (1+4x)

⇒ 1+4(4)

⇒ 1+16

⇒ 17 hours.

∴ Tracie drove for 17 hours.