Question: Hilary is collecting her toenails in a jar to gross out her sister. She can fit 100 toenails in the jar, unless they are from her two big toes, which are twice as big as the rest. She has already filled it with 20 big toenails and 40 regular toenails. How many regular toenails can she fit into the remainder of the jar? Think carefully first, then make a decision:
The 20 big toenails take up as much space as 40 regular toenails because 20 x 2 = 40. She has filled up 80 toenails worth because 40 + 40 = 80. She can fit 20 regular toenails in the jar because 100 - 80 = 20. So the answer is 20.