In an office comprising 200 people, 25% people are between the age of 20-25 years, 35% between the age of 25-30 years, 30% between the age of 30-35 years and 10% above the age of 35 years. Calculate the total number of people working in the office between the age of 20-30 years.
200 * 0.25 + 200 * 0.35 = 200 * 0.6 = 120