Actually, we can remove one of the arrays:

=SUMPRODUCT(--(MMULT(--(ISNUMBER(MATCH(A$1:F$3,A10:B10,0))),{1;1;1;1;1;1} )=2))

Biff

"T. Valko" wrote in message
...
Will any numbers be repeated on any single row:

Row 1 = 2,1,7,10,8,5
Row 2 = 5,10,11,12,20,1
Row 3 = 15,10,16,17,18,1

Is this possible:

Row 1 = 1,1,1,10,10,5

Based on you sample which doesn't have any repeats per row:

..........A..........B
10......5..........10
11......1..........10

Enter this formula in C10:

=SUMPRODUCT(--(MMULT((ISNUMBER(MATCH(A$1:F$3,A10,0)))+(ISNUMBER( MATCH(A$1:F$3,B10,0))),{1;1;1;1;1;1})=2))

Copy down to C11

Biff

"Will" wrote in message
...
Dear Experts,

Which Formula shd I use so as to compute how many times a certain pair of
numbers appeared in a few groups of 6 numbers

example

1st group of 6 numbers: 2 (A1), 1 (B1), 7 (C1), 10 (D1), 8 (E1), 5 (F1)
2nd group of 6 numbers: 5 (A2), 10 (B2), 11 (C2), 12 (D2), 20 (E2), 1
(F2),
3rd group of 6numbers: 15 (A3), 10 (B3), 16 (C3), 17 (D3), 18 (E3), 1
(F3),
..
..
..

Number (5 & 10) appear: 2 times
Number (1 & 10) appear: 3 times

I tried to use countif but it only enable me to match a Single range with
a
Single citeria but now i have multiple Range to match with 2 citeria.