Answer:
142 mL
Step-by-step explanation:
In order to find the answer for this question, we'll need to find the average of the two values, because that will tell us how much each person will have after the exchange. We can then subtract that from Theo's initial amount to get what he gives to Poppy. There are other ways to do this, this is just one way.
To find the average, we'll first add the two values together. 500 + 216 = 716.
Then, we divide this by 2, as that's the number of values we initially added together. 716 / 2 = 358.
Finally, we subtract this from Theo's initial value. 500 - 358 = 142.
That gives us our final answer of 142 mL. We can add this to Poppy's initial value to check our answer, 216 + 142 = 358.
Hope this helps! Let me know if you have any questions :D