The cargo van traveled a third of the way at a speed of 90 kilometers per hour in 8 hours. How long is it left to drive?

To solve this problem, we introduce the conditional variable “X”, through which we denote the path that the cargo van must travel.

In 8 hours, the van traveled 8 x 90 = 720 kilometers.

Then, based on the data of the problem, we will compose the following proportion: 1/3 refers to 720 kilometers as 1 refers to X kilometers.

Then, based on this proportion, we will compose the following equation: X x 1/3 = 720 x 1.

Solving this equation, we get X = 720 x 3 = 2160 kilometers.

Therefore, the van has to travel 2160 – 720 = 1440 kilometers.

Answer: 1,440 kilometers.