Correct Answer - Option 3 : 90 km

**Given:**

The distance covered by foot = (7/12) of the total journey

The distance covered by bus = (3/5) of the remaining journey

The distance covered by car = 15 km

**Calculation:**

Let the distance of the entire journey be D km.

The distance covered by the person by foot = (7/12) × D

⇒ 7D/12

The remaining distance to complete the journey = D - (7D/12)

⇒ 5D/12

The distance covered by the person by bus = (3/5) × (5D/12)

⇒ (3D/12)

Completed journey = (7D/12) + (3D/12)

⇒ 10D/12

The remaining journey = D - (10D/12)

⇒ 2D/12

According to the question,

2D/12 = 15

⇒ D/6 = 15

⇒ D = 15 × 6

⇒ D = 90 km

**∴ The length of the entire journey is 90 kilometers.**