Four different sets of objects contain 2 4 6 and 7 objects respectively. How many unique combinations can be formed by picking one object from each set?

336

2 possibilities for the first

for each of these two you have 4 possibilities for the second - making it 8

for each of these 8 you have 6 possibilities for the third - making it 48 possibilities

for each of those 48 you have 7 possibilities for the fourth - making it 336 possible combinations

2x4x6x7 = 336