Question 18
What is the least number of distinct even numbers that must be selected from the list of 80 numbers 21, 22, 23, …, 99, 100 to guarantee that two selected numbers have sum 100?
Answer format: enter one whole number without units; leading zeros are optional. The source answer sheet uses four digits (for example, 7 is shaded as 0007).
Answer format: enter one whole number without units; leading zeros are optional. The source answer sheet uses four digits (for example, 7 is shaded as 0007).