Question

WHAT IS THE SUM OF ALL THE DISTINCT, POSITIVE PRIME FACTORS OF 1260

Answer 1

You have to break 1260 down into it's number tree. Start by dividing the number by 2 until you can't do it evenly, then divide by 3, and so on until no more divisions can be made:

1260/2 = 630

So we have one prime factor, 2 and are left with 630:

630/2 = 315

Now we have two prime factors, 2 and 2. We are left with 315:

315/3 = 105

Now we have three prime factors - 2,2,3. We are left with 105:

105/3 = 35

Now we have four prime factors - 2,2,3,3. We are left with 35:

35/5 = 7

Now we have SIX prime factors - 2,2,3,3,5,7. Thus the sum of all the distinct, positive prime factors of 1260 are:

2+2+3+3+5+7 = 22