Answer:
18 jujubes
Explanation:
The easiest way to solve this problem is to work backwards.
Kim has the last 10 jujubes.
If Kyle kept 8 jujubes after giving 10 to Kim, then Kyle had: 10 + 8 = 18 jujubes.
If Jen ate 1/2 of the jujubes and gave the rest to Kyle, then Kyle had 1/2 of Jen's jujubes. Therefore, Jen had 18 × 2 = 36 jujubes.
Therefore, Jen ate 18 jujubes.