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

Redeem

GMAT Prep Ques

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Wed Mar 07, 2007 11:04 pm

GMAT Prep Ques

by rajatmehta » Sun Jun 03, 2007 12:14 am
Could somebody kindly post solution to the following problems:

1. For all positive integers m, fn(m) = 3m, when m is odd, and fn(m) = (1/2)*m, when m is even. Which of the following is equivalent to
fn(9)*fn(6)? Answer: 27

2. When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year? Answer: 2/3

Thanks
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 56
Joined: Tue Feb 13, 2007 6:19 am

by zozo123 » Sun Jun 03, 2007 10:57 am
1. For all positive integers m, fn(m) = 3m, when m is odd, and fn(m) = (1/2)*m, when m is even. Which of the following is equivalent to
fn(9)*fn(6)? Answer: 27


9 is odd then fn(9) = 3*9 = 27
6 is even then fn(6) = 1/2 * 6 = 3

fn(9)*fn(6) = 27 * 3 = 81


2. When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year? Answer: 2/3

Important : the height of the tree increased by a constant amount each year for the next 6 years. If X is the amout incresead each year.

Then,for the next 6 years we can write : 4+x+x+x+x+x+x = 4 + 6x

At the end of the 4th year : 4 + 4x


At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year => 4+6x = (4+4x) + 1/5*(4+4x)

=> Resolve the equation and obtain x = 2/3
Top
Post new topic Post Reply
• Page 1 of 1