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If the product of the integers a, b, c, and d is 1,155 and if a > b >
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07 Apr 2015, 10:00

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1155 is divisible by 11 from the first glance, which lets us easily split it into 11*105 and then into 11*7*5*3. As it turns out we don't have to think much about possible products of 4 numbers, because we pretty much got 4 numbers for 4 spots and after arranging them in the corresponding order its easy to figure out that the answer is 11 - 3 = 8 which matches answer D

Upon first glance, 1155 and four variables might look really messy. But take the first step – you know it’s divisible b y 11 and that you have to factor it. 1100 is 11*100 and 55 is 11*5, so you have 11*105. And 105 is much easier to divide out since it ends in a 5. That’s 21*5, which is 7*3*5. Once you’ve factored it down, it’s 11*7*5*3, which are all prime, so when 1 has to be less than any of these, that’s exactly a, b, c, and d. You need the biggest minus the smallest, and 11-3 is 8. What may have looked like a big, intimidating number was actually not so bad once you took the first step. It’s always darkest before the light goes on.

Re: If the product of the integers a, b, c, and d is 1,155 and if a > b >
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05 Mar 2017, 02:06

Hello everybody! I have a confusion, whether this factorization technique is the way to approach such type of question or it's appropriate with the information given in the question. For instance i have a number 910 which is the product of abc where a>b>c and i have to find a-c. If I take factorization technique there are four prime factors of 910, which is 2,5,7,13, so if i take 2,35(5x7),13 then answer is 33. however if i take, 10(2x5),7,13, answer is 6. Because the question ask me that a,b,c,d are integer and integers could b prime and non-prime as well.

Re: If the product of the integers a, b, c, and d is 1,155 and if a > b >
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05 Mar 2017, 02:21

Ahtisham wrote:

Hello everybody! I have a confusion, whether this factorization technique is the way to approach such type of question or it's appropriate with the information given in the question. For instance i have a number 910 which is the product of abc where a>b>c and i have to find a-c. If I take factorization technique there are four prime factors of 910, which is 2,5,7,13, so if i take 2,35(5x7),13 then answer is 33. however if i take, 10(2x5),7,13, answer is 6. Because the question ask me that a,b,c,d are integer and integers could b prime and non-prime as well.

I don't think that questions would be that confusing. Even if there are given just 3 integers (a,b,c) there will be given a>b>c>2.