Answer:
23
Step-by-step explanation:
1. according to the condition 'Bob is 3 years older than twiceJohn's age':
B-2J=3;
2. according to the condition 'The sum of their ages is 33':
B+J=33
3. If to solve these two equations as a system, then
[tex]\left \{ {{B+J=33} \atop {B-2J=3}} \right. \ => \left \{ {{B=23} \atop {J=10}} \right.[/tex]
