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How many strings with 5 or more characters can be formed from the letter SEERESS ?

Verify the answer ...
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1 Answer

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Correct it where I am Wrong...

S = 3 E = 3 R=1

Strings can be 5 letters or 6 letters or 7 letters..

 Seven Letters :  (7! / 3!*3! ) = 140

Six Letters : We can take out either S or E or R =  ( 6! / 3!*2! ) + ( 6! / 3!*2! )  + (6! / 3!*3!) = 140

Five Letters : We can take out either {SE} or {ER} or {SR} or {EE} or {SS} = ( 5! / 2!*2! ) + ( 5! / 2!*3! ) + ( 5! / 2!*3! ) + 2*( 5! / 3! )  = 90

Final Answer = 140 + 140 + 90 = 370
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