Question

Anna, Irina, Avel, and Vlad are going on a road trip. The following table shows an incomplete probability model for who will be driving during any given kilometer.

Anna: 1/8
Irina: 3/8
Avel: ?
Vlad: 1/8

If the road trip involves 640km of driving, which of the following is the best prediction for the number of kilometers that Avel will drive?
A. 80
B. 160
C. 240
D. 320

Answer 1

3/8

Explanation:

Khan Academy. Boom.

Answer 2

1.
`(3)/(8)`

2. 240 km

Explanation:

Anna drives
`(1)/(8),` Irina drives
`(3)/(8),` Vlad drives
`(1)/(8),` then Avel drives

`1-(1)/(8)-(3)/(8)-(1)/(8)=(8)/(8)-(1)/(8)-(3)/(8)-(1)/(8)=(8-1-3-1)/(8)=(3)/(8).`

If the road trip involves 640 km of driving, then Avel drives

`640\cdot (3)/(8)=80\cdot 3=240\ km.`