Remainder 1 - Must be true - The Beat The GMAT Forum - Expert GMAT Help & MBA Admissions Advice

BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Remainder 1 - Must be true

This topic has expert replies

Post new topic Post Reply

Previous Topic Next Topic

lamhe: Junior | Next Rank: 30 Posts; Posts: 22; Joined: Mon Feb 19, 2007 6:26 pm

Remainder 1 - Must be true

by lamhe » Thu May 21, 2009 5:54 pm

For any positive integer x, (x) is defined to be the remainder when 3x is divided by 2, which of the following must be equal to 1?

I. (2x+1)
II. (2x)+1
III. 2(x+1)

(A) I only
(B) II only
(C) III only
(D) I and II
(E) I, II, and III

Vishal

Quote

Source: Beat The GMAT — Problem Solving | Thu May 21, 2009 5:54 pm

cramya: Legendary Member; Posts: 2467; Joined: Thu Aug 28, 2008 6:14 pm; Thanked: 331 times; Followed by:11 members

by cramya » Thu May 21, 2009 8:28 pm

Would go with [spoiler]D)[/spoiler]

I can substitute any x since its true for all x or do it algebrically

I. (2x+1)

3(2x+1) / 2 = 6x/2+3/2 = 0+1 remainder 1

II. (2x)+1

3(2x)/2 + 1 = 0+1 = remainder 1

III. 2(x+1)

Remainder cannot be 1

2 3(x+1) /2 = remainder cannot be 1 so not part of must be true

Hope I dint misinterpret something here(Stmt iii).

Regards,
CR