103 14 Television and radio stations use four call letters s

10.3 #14

Television and radio stations use four call letters starting with W or K, such as WXYZ or KRLD. Assuming no repetitions in the second to fourth letters, how many four-letter sets are possible using either W or K and only the letters C to U? (Count all possibilities even though, practically, some may be inappropriate.)

There are _____ four-letter sets that can be formed.

(Checked and 10,710 is not the answer)

Solution

2 ways (W or K) *19 ( C to U) * 18 * 17 = 11628

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