While digging in his back yard, a neighborhood boy found a strange rock emitting a strange light.He set it on his front porch, and after 5 days it had shrunk to half the size it was when he found it.In another 5 days it had shrunk again to half the size it was 5 days earlier.He realizes that whatever the material is, it has a half-life of 5 days.Whatpercentageof the rock was left (compared to when he found it) after it had been sitting on the front porch for 9 days?