Graduation has 10 letters -- 5 constants, 5 vowels The number of ways this words can be scrambled to end up with the first two constants is 5.4.3.2.1.5.4.3.2.1=14400 The number of ways this words can be scrambled in total is 10.9.8.7.6.5.4.3.2.1=3628800 Therefore, probability of first two being constant is$\frac{ 14400 }{ 3628800 }=\frac{ 1 }{ 252 }$