Correct Answer - Option 1 : 21 m

**Given:**

The tower of height 20 m casts a shadow of 12 m.

**Calculation:**

As, the tower of height 20 m casts a shadow of 12 m.

∴ The tower of 1 m length, casts shadow of (12 ÷ 20) m

⇒ The shadow casts by 35 m tree = (12 ÷ 20) × 35

= 21 m

**∴ The tower of length 35 m casts 21 m of shadow.**