Three variables x, y and z take values 2, 3, 4 or 5 such that their values are always distinct. If M and N denote the largest possible value and the smallest possible value, respectively, for the expression {(x × y) + z}; then M - N is

x, y, z take distinct values from {2,3,4,5}. To maximize (x×y)+z: choose largest two for x,y product and any remaining for z. Try x=4, y=5, z=3: (4×5)+3 = 23. Try x=5,y=4,z=3: same = 23. Try x=5,y=3,z=4: 15+4=19. So M = 23. To minimize: choose smallest two for product, smallest remaining for z. x=2,y=3,z=4: 6+4=10. x=2,y=3,z=5: 6+5=11. x=2,y=4,z=3: 8+3=11. So N = 10. M - N = 23 - 10 = 13.