For combinations question, why do you times but not add up?
e.g 6C3 * 4C2=120, why is it not 6C3 + 4C2 ?
It's so confusing.
Please explain clearly.
2006-12-11 22:48:08 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
think of rolling 2 dice. how many different combinations can you come up with. there are 6 different numbers on each die. if you added 6+6 you only get 12 combinations. but we know that cant be true. its more like 6*6 or 36 different combinations.
you can roll a
1 and 1
1 and 2
1 and 3
1 and 4
1and 5
1 and 6
2 and 1
2 and 2
2 and 3
2 and 4
2 and 5
2 and 6
3 and 1
3 and 2
3 and 3
3 and 4
3 and 5
3 and 6
and so on..........
2006-12-11 23:02:26 · answer #1 · answered by tma 6 · 1⤊ 0⤋
6C3=6*5*4/3*2*1=5*4=20
4C2=4*3/2*1=6
then 6C3+4C2=20+6=26 and 6C3*4C2=20*6=120
2006-12-11 23:01:13 · answer #2 · answered by grassu a 3 · 0⤊ 2⤋
When the events are connected with one another, you need to multiply the various events together to get the total result. When however these events occur independently of one another, the only way to obtain the total result is to add them together
2006-12-11 23:08:53 · answer #3 · answered by Paleologus 3 · 0⤊ 0⤋
You must write the problem.
Add or multiply? Depends on the problem and not of the formula.
2006-12-11 23:10:33 · answer #4 · answered by vahucel 6 · 0⤊ 2⤋