Answer:
In 68 years, the population will be 600,000
Explanation:
Population of the city is 150000
It doubles every 34 years, that is 34 years from now, it will be
150000 × 2 = 300000
In 68 years, which is another 34 years, it will be double of 34 years or 4 times the original population, that is
300000 × 2 = 600000, or
150000 × 4 = 600000