🦘 Math Kangaroo Grade All Felix 1-2 Ecolier 3-4 Benjamin 5-6 Kadett 7-8 Junior 9-10 Student 11-12 ⇄ switch contest
2023 Math Kangaroo

Problem 13

Problem 13 · 2023 Math Kangaroo Stretch
Logic & Word Problems work-backwardcareful-counting

Each of the children Ali, Lea, Josef, Vittorio and Sophie gets a birthday cake. The number on top of the cake shows how old the child is. Lea is two years older than Josef, but one year younger than Ali. Vittorio is the youngest. Which cake belongs to Sophie?

Figure for Math Kangaroo 2023 Problem 13
Show answer
Answer: C
Show hints
Hint 1 of 3
There are five cakes with five ages on them — match a child to each one.
Still stuck? Show hint 2 →
Hint 2 of 3
Use the clues to label the easy children first, and give the smallest cake to Vittorio.
Still stuck? Show hint 3 →
Hint 3 of 3
Sophie gets the one cake that is left over after everyone else is matched.
Show solution
Approach: match the easy children first; Sophie gets the leftover cake
  1. Josef, then Lea (2 older than Josef), then Ali (1 older than Lea) line up in a row of ages.
  2. Vittorio is the youngest, so he takes the smallest-numbered cake.
  3. Four children are now placed, so the one cake left over is Sophie's: the cake showing 6, option C.
Mark: · log in to save