Enter following values/formula into cells A1:C8, for
example:
2001 0.31 =MAX((A1A2:A8)*(B1B2:B8)*C2:C8)
500 0.5 1
750 0.5 2
1000 0.35 2
1000 0.5 4
2000 0.3 2
2000 0.35 3
2000 0.4 5

Formula in C1 has to be entered as array formula (hit
CTRL+SHIFT+ENTER, not only ENTER).

Just a hint: Maybe you want to use = instead of ?!

HTH,
Bernd