Answer:
23 cards.
Step-by-step explanation:
After Monday, Esteban has 12 cards.
After Tuesday, Esteban has 12 + 24 = 36 cards.
He gave to his sister x cards.
36 - x = 13
36 = 13 + x
23 = x
That would be the median....u need to list the numbers in order to find the middle number (median)
