10C0 + 9C1 + 8C2 + 7C3 + 6C4 + 5C5

= 1+9+28+35+15+1

= 89

+2 votes

A staircase has 10 steps , you can walk up taking one or two steps at a time . how many ways can go up to top of stair ?

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my solution is of fibonacci series , like for 1step ==1 , 2nd step 1+1 or 2 ==2ways , 3rd step 1+1+1 or 1+2 or 2+1 ==3ways , so ,1,2,3,5,8,13,21,34,55,89 , for 10th step 89 ways .