Deal 8
 
  3NT
OL: 5
♠ 8 5 2
A K Q J 10
8 3
♣ Q 10 6
 
 WEST  NORTH  EAST  SOUTH
1♣
pass1pass1NT
pass3NTpasspass
pass

You are West. The bidding has been as shown.

You lead the 5; 3, 10 and won by South with K.
South now leads the ♣9 from his hand and it is your play.

When you have made your choice click NEXT .
♠ K Q 4
7 4
J 9 7 5 4
♣ A J 3


10
 

K
♣ 9
 

 
Deal 8
 
  3NT
OL: 5
♠ 8 5 2
A K Q J 10
8 3
♣ Q 10 6
  Play the ♣A.

First ask yourself "Where are the A and Q?"
East doesn't have either one or he would have played it at the first trick.
So South has both of them.
So with those 3 tricks and the 5 s in dummy South only needs to find one more winner. Assuming he has the ♣K, (or why play the suit), if you play low he will find that one more winner whichever high ♣ he plays.

Next ask yourself "Where is the ♠A?"
Clearly East DOES have this card; otherwise South has his 9 tricks.

So the way to beat the contract is to go up with your ♣A, then play ♠K, ♠Q and a third ♠, hoping East holds ♠ A x x x.

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