If n is an even integer and denotes that the product of all the

Question

If n is an even integer and denotes that the product of all the even positive integers to n. For example, = 2 * 4 * 6 * 8 * .... * n. What is the greatest prime factor of <20> + <22>? A. 19 B. 21 C. 23 D. 27 E. 31 Got this question from my offline GMAT prep course I signed up for last week.. Can anybody help me actually solve this problem please?? Also, how can I tag this post properly?

pushpitkc · Accepted Answer

Hey HappyQuakka , Since = 2*4*6*8*10*12*.... n <20> = 2*4*6*8*10*12.... 20 <22> = 2*4*6*8*10*12.... 22 Therefore <20> + <22> = 2*4*6*8*10*12.... 20 + 2*4*6*8*10*12.... 20*22 = 2*4*6*8*10*12.... 20(1+22) = 2*4*6*8*10*12.... 20*23 Hence the greatest prime factor must be 23(Option C) Hope that helps!

Bunuel · Answer

Luckisnoexcuse · Answer

<20> + <22> = <20> (1 + 22) = <20> * 23 C

reachskishore · Answer

I guess the question stem here should say "<n> denotes that the product of all the positive EVEN integers to n" only then we can solve it the way you have done. Please correct me if I am wrong

siddharthkapoor · Answer

= 2*4*6*8*10*12*...*n => <20> = 2*4*6*8*10*12...*20 and <22> = <20>*22 Thus, <20> + <22> = <20>(1+22)=<20>*23 None of the terms in <20> is a prime number, except 2, so 23 is the greatest prime factor of <20> + <22>. Therefore, the correct answer is option C.

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If n is an even integer and <n> denotes that the product of all the

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