In a knock-out tennis tournament, six of the quarterfinal, semifinal, final results are: Bella beat Ann; Celine beat Donna; Gina beat Holly; Gina beat Celine; Celine beat Bella; Emma beat Farah. Which result is missing?
Jill makes a multiplicative magic square using 1,2,4,5,10,20,25,50,100 once each. Products in every row, column and both diagonals are equal. The start is shown. What belongs in the question-mark cell?
Eight unmarked envelopes contain 1,2,4,8,16,32,64,128. Eve chooses some, Alie takes the rest. Eve’s sum is 31 more than Alie’s. How many envelopes did Eve choose?
There are 2016 kangaroos, each grey or red, and both colors occur. For each kangaroo K take number of opposite-color kangaroos divided by number of same-color kangaroos, including K. What is the sum of all 2016 fractions?