Maths Olympiad Prep

Library / /69 of 168

Algebra Difficulty 1.8 Junior Find the answer

The average age of Andras, Frances, and Gerta is 22 years. Given that Andras is 23 and Frances is 24, what is Gerta's age?

A number or a short expression. Spacing and $ signs are ignored.

Solution

Since the average of the three ages is 22, the sum of the three ages is 3×22=66 3 \times 22 = 66 . Since Andras' age is 23 and Frances' age is 24, then Gerta's age is 66−23−24=19 66 - 23 - 24 = 19 .

Want a route through all this instead of an archive? The track puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.

Source: Omni-MATH, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.