A person buys eight packets of TIDE detergent. Eachpacket contains one coupon, which bears one of the let-ters of the word TIDE. If he shows all the letters of theword TIDE, he gets one free packet. If he gets exactlyone free packet, then the number of different possiblecombinations of the coupons is

A shoping mall is running a scheme: Each packet of detergent SURF contains a coupon which bears letter of the word SURF, if a person buys at least four packets of detergent SURF, and produce all the letters of the word SURF, then he gets one free packet of detergent. If person buys 8 such packets, then the probability that he gets exactly one free packets is

A shopping mall is running a scheme: Each packet of detergent SURF contains a coupon which bears letter of the word SURF, if a person buys at least four packets of detergent SURF, and produce all the letters of the word SURF, then he gets one free packet of detergent. If a person buys 8 such packets, then the probability that he gets two free packets is