Answer:
The fourth person is 34 years old.
Step-by-step explanation:
Step 1: Find ages of the 3 people running for election
42*3=126 Their ages combined is 126.
Step 2: Find the ages of the 4 people running for election.
40*4=160
Step 3: Subtract the two ages.
160-126=34.
The 4th person is 34.