Bidding : 1NT (N) - 3NT (S) - Pass (N)
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Opening Lead : 4 of Hearts (E) = 4th card from his longest suit

Declarer (N) counts 7 sure winners : three in Spades, one in Hearts, two in Diamonds and one in Clubs. A Diamond finesse is the best option, for even if the finesse loses it can provide the two additional tricks.

Declarer Play
Hold Up   -   Avoidance play
East's 4 of Hearts looks like the 4th card of a 5 card suit. Therefore Declarer holds up the Heart suit twice, and wins the 3rd trick with the Ace.
East is the dangerous Opponent with the two remaining Heart winners in his hand. At trick 4 Declarer leads the Diamond Ace, then the 10. East and Dummy play low and West wins the trick with the Queen.
East now can not lead Hearts anymore and any other lead is won by Declarer. Declarer now cashes his sure winners : three Spades, three more Diamonds and the Club Ace and make 9 tricks for his contract. If Declarer tries to finesse the Clubs at any point he will not make his contract.

Score = 40 + 2 x 30 trick pts + 500 bonus pts = 600 pts total

Bidding : 1NT (E) - 2C* (W) - 2S (E) - 3NT (W) - Pass (E)
* = Stayman Convention

Opening Lead : King of Hearts (S) = top of a solid sequence

Declarer (E) counts 8 sure winners : the Aces of Spades and hearts, A K Q J of Diamonds and A K of Clubs. The 9th trick can be provided by the Club suit.

Declarer Play
Stayman Convention   -   Hold Up   -   Avoidance play
Declarer holds up the first round of Hearts to guard against a 5-2 spilt in Hearts, winning with the Ace at trick 2.
He now must keep South off the lead and therefore, at trick 3, plays the Ace of Clubs, followed by the Jack (trick 4) for a finesse against South's Queen. Both South and Dummy play low and North wins with the Queen.
North can do no harm however, as he is out of Hearts to lead to his Partner. His small Spade lead is won by Declarer who then proceeds to win 8 more tricks, four in Diamonds and four in Clubs. He only concedes a Spade trick at the end, making a total of 10 tricks.

Score = 40 + 3 x 30 trick pts + 500 bonus pts = 630 pts total

Bidding : 1NT (S) - 3NT (N) - Pass (S)

Opening Lead : 5 of Clubs (W) = 4th card from the top

Declarer (S) counts 6 sure winners : A K in Spades, A K Q in Hearts plus the Ace of Diamonds.
He can develop more winners in Diamonds and one in Clubs.

Declarer Play
Hold Up   -   Avoidance play
On the opening lead East plays his Jack of Clubs and Declarer, seeing that he can the potentially dangerous Opponent (West) off the lead, holds up once. East leads another Club on which Declarer plays his Queen which is captured by West's Ace. At trick 3 West leads a third Club, won by Declarer with his King.
Declarer now leads the Diamond Queen for a direct finesse against the King. East wins but is out of Clubs to lead to his Partner. Instead he leads a small Spade, Declarer plays low, West plays the 10 and Dummy wins with the King. Declarer then proceeds to win 8 more tricks, one in Spade, three in Hearts and four in Diamonds, making 10 tricks total.

Score = 40 + 3 x 30 trick pts + 500 bonus pts = 630 pts total

Bidding : 1NT (W) - 3NT (E) - Pass (W)

Opening Lead : 7 of Hearts (N) = 4th card from the top

Declarer (W) counts 6 sure winners : Ace of Spades, A K Q of Diamonds and A K of Clubs.
Additional winners can come from the Club suit plus an extra Heart or Spade trick.

Declarer Play
Hold Up   -   Avoidance play
South plays the Heart Queen on the first trick and Declarer, guarding against a 5-2 Heart split holds up once. On the Heart return Declarer plays the Jack which is captured by North's Ace. North now plays a third Heart which is won by Declarer's King.
Normally, holding a total of 9 Clubs, Declarer would not finesse the Queen but play the Ace and King hoping for a drop instead.
This time however he must keep North off the lead and therefore must take the Club finesse. Therefore at trick 4 Declarer plays his Club King followed (trick 5) by a small Club to Dummy's Jack. At trick 6 Dummy plays the Club Ace which captures North's Queen. Declarer then proceeds to win 6 more tricks, two in Clubs, three in Diamonds plus the Spade Ace, making a total of 10 tricks. He must not take the Spade finesse as this would bring North on lead if it fails.

Score = 40 + 3 x 30 trick pts + 300 bonus pts = 430 pts total