51 (fifty-one)
The answer is: 49
51
1 + 44 + 5 - 50 = 0
2099
4.9 + 1 = 5.9
53
78 + 50 = 128
50
1+2 = 3 1+2+3 = 6 1+2+3+4 = 10 1+2+...+ N = 1/2(N+1)N if N = 50, 1+2+...+50 = 1/2 x 51 x 50 = 1275 Since 2+4+6+...+100 = 2 x (1+2+3+...+50) = 2 x 1275 = 2550
91
Neither. It is 50 minus 10 plus 5 plus 1 plus1plus1.
65 + 65 + 65 + 90 + 90 + 90 + 90 + 50 + 50 + 50 + 50 + 50 + 50 + 20 + 20 + 20 + 20 + 20 + 20 + 20 = 995
186 100 + 50 = 150 150 + 20 = 170 170 + 10 = 180 180 + 5 = 185 185 + 1 = 186 Easy see! =)
1 plus 2 plus 3 plus 4 equal 10. 10 times 5 equals 50.