Question

The Smith family has three children: Tom, John, and Andy. Tom is younger than Andy. John is not older than Tom. From youngest to oldest, how are the children ordered by age?

Answer 1

Age of tom=t
age of john=j
age of andy=a

t<a
if j is not older than t, then he is less than or equal to t so
j ≤ t
but there is an oldest so therefor we assume that j < t
t < a
j < t
subsitute
j<t<a
andy is oldest
tom is second
john is youngest