Correct Answer - Option 3 : 1 1/2 hr

**Given:**

Speed = 45% = 9/20

Time = 1 hour 50 min = 11/6

**Formula used:**

Speed = Distance/Time

Speed is inversely proportional to time

**Calculation:**

Let the speed of the man be 20x

45% of the speed = 20x × 9/20

⇒ 9x

Ratio of speed of man before and after = 20x : 9x

As we know that, speed is inversely proportional to time

Time ratio of man before and after = 9x : 20x

According to the question

⇒ 20x/9 – x = 1 hr 50 min = (1 + 50/60) hr

⇒ 11x/9 = 11/6

⇒ 11x = 11 × 9/6

⇒ 11x = 33/2

⇒ x = 3/2 hr

⇒ 1 1/2 hr

**∴ The usual time to reach the destination is 1 1/2 hr**