MHTCET 18 Apr 2026 Shift 2 Paper

Concept:In an echo, sound travels to the reflecting surface and returns to the listener, so the total distance travelled by sound is twice the distance between the listener and the reflecting surface.Explanation:Let $d_1$ be the distance of the person from the nearer cliff.For the first echo heard after $1$ second:$$2d_1 = 330 \times 1$$$$2d_1 = 330$$$$d_1 = \frac{330}{2} = 165 \text{ m}$$So the person is $165$ m from one cliff.Let $d_2$ be the distance of the person from the other cliff.For the second echo heard after $3$ seconds:$$2d_2 = 330 \times 3$$$$2d_2 = 990$$$$d_2 = \frac{990}{2} = 495 \text{ m}$$So the person is $495$ m from the other cliff.Since the person stands between the two parallel cliffs, the distance between the cliffs is the sum of the two distances:$$d_1 + d_2 = 165 + 495 = 660 \text{ m}$$Answer:The distance between the two cliffs is $660$ m.Therefore, the correct option is B.