#include <stdio.h> #include <math.h> float getage(int w,float y,double x,int newage) { return (1-x)*(y+1)+x*newage; } int main() { int w,n; float x,y; while(scanf("%d %f %f %d",&w,&y,&x,&n)!=EOF){ float answer; while(n>0) { answer=getage(w,y,x,21); y=answer; n--; } int...