Correct Answer - Option 2 : 10.88%

**Given:**

The number of bacteria decreases in first hour = 4%

The number of bacteria increases in second hour = 5%

The number of bacteria increases in third hour = 10%

Total number of bacteria = 500,000

Time = 3 hours

**Calculation:**

According to the question

⇒ (500,000 × 96/100 × 105/100 × 110/100)

⇒ (500,000 × 24/25 × 21/20 × 11/10)

⇒ 554,400

Now,

⇒ (554,400 – 500,000)

⇒ 54,400

Required percentage = (54,400/500,000 × 100)

⇒ (272/25)%

⇒ 10.88%

**∴ Required percentage increase is 10.88%**