It just math formula within context. Put something like; 
(Trigger once) 
	if seed_A.pickedCount equal or greater than 1 >> add 1 to multiplier var
					or
	if seed_B.pickedCount equal or greater than 1 >> add 1 to multiplier var
					or
	if seed_C.pickedCount equal or greater than 1 >> add 1 to multiplier var
Score example: (seed_A.Count*50 + seed_B.Count*50 + seed_C.Count*50)*multiplier var
Something like that depend on your formula.
I am not able to implement this formula.
I want to score "sustainability" I have 3 types of plants, I want if at the time of harvesting plant A, it is on the side of plant B or C, increase the sustainability score.