Deal 9
 
  3NT
♠ K 9 2
Q 10 9 8 5
A 6
♣ A 10 6
 
 WEST  NORTH  EAST  SOUTH
1pass2NT
pass3NTpasspass
pass

The bidding has been as shown.
Partner led the ♠5, dummy played the ♠2 and it is your play.

When you have made your choice click NEXT .
♠ 5


♠ A J 7
6 4 2
10 9 8 5
♣ 9 7 3
 


 

 
Deal 9
 
  3NT
♠ K 9 2
Q 10 9 8 5
A 6
♣ A 10 6
  Play the ♠7.

Partner's low ♠ lead tells you he has an honor in the suit, so it must be either the ♠Q or the ♠10.
South's jump to 2NT makes it almost certain that he holds the ♠Q, so you can figure partner probably led from ♠ 10 x x 5.

Apply the Rule of 11. 11 minus 5 = 6 cards higher than the ♠5 held by dummy, you, and declarer. Since you can see 5 of the 6 you conclude that that declarer will have to play his ♠Q to beat your ♠7.

South will take the ♠Q at trick 1, but when West wins a high he will play another ♠ through dummy's ♠ K 9 to your ♠ A J. Once you clear dummy's ♠ away partner will win another and be able to cash his last ♠.

Note that if dummy's ♠9 was played you would cover with your ♠J, leading to the same situation.

 Deal 10 
♠ 10 8 6 5
A K 3
Q 7 2
♣ 8 4 2
♠ A J 7
6 4 2
10 9 8 5
♣ 9 7 3
  ♠ Q 4 3
J 7
K J 4 3
♣ K Q J 5