4. Consider a muevel computer in which all the levels are different. Each level has in- structions that are m times as powerful as those of the level below it; that is, one level r instruction can do t k seconds to run, how long would equivalent programs take at levels 2, 3, and 4, as suming n level r instructions are required to interpret a single r+ 1 instruction? he work of m level r - 1 instructions. If a level-1 program requires