A man beats drum at a certain distance from a large mountain. He slowly increases the rate of beating and finds that the Echo is not heard distinctly when the drum beating is at the rate of 40 per minute. he moves by 80m toward the mountain and finds that the Echo is again not heard distinctly when the rate of the beating of the drum is 1 per second what is the initial distance of the man from the mountain? (1)120m;(2)240m;(3)270m;(4)340m

Lee Merlin , 6 Years ago

Grade 12