CP #23

From GMATClub.com's m#05:


4. Two watermelons, A and B, are on sale. Watermelon A has a circumference of 6 inches; watermelon B, 5 inches. If the price of watermelon A is 1.5 times the price of watermelon B, which watermelon is a better buy?

(Assume that the two watermelons are spheres).

(C) 2008 GMAT Club - [t]m05#4[/t]

• A
• B
• Neither
• Both
• Impossible to determine

 

Approach 1:

Value = Volume / Price

The volume is proportional to radius^3 and the circumference is proportional to the radius. Increasing the circumference by 6/5 = 20% increases the volume by 1.2^3 = 1.728 (72.8%) and increases the price by 50%.

The increase in value of Watermelon A is 1.728 / 1.5 = 15.3% .

Numbers

Did some questions from the Geometry chapter of a Career Launcher book. Learnt the alternate segment theorem which was not mentioned in GMATClub's Math Book - Geometry chapter.

Have begun Number Theory today.

Oh, and also, was on a crazy project putting in long hours so was unable to study. Dance class has moved to Monday & Thursday now, and should be back home by 8 max on these days, so waking up early is no longer a worry and my weekends are completely free to study. :-) It's looking good guys!

And it's a wrap.

Done with Geometry Theory. Got 38/42 correct in Kaplan book's practice sets. 3 questions - very silly mistakes. 1 question - although easy, it had a particular method to solve it. It's definitely a CP. Will post it soon.

Now starting off with Standard Deviation.

How To Wrap Up The Geometry Theory Module Perfectly

Geometry theory from OG - check.

Geometry theory from GMATClub's Math book - check.

Go through FCs to drill the formulae into your brain - partially done.

Geometry theory from Kaplan - pending.

Action Plan (from BTG's 60-Day Study Guide: Day 15)

To Do:

• In Kaplan's GMAT 2010-2011 Premier with CD-ROM:
• Read the section on Lines and Angles (p. 293-295)
• Answer questions 1, 3 and 4 on the Lines and Angles Practice Set (p. 296-297)
• Read the section on Triangles (p. 299-404)
• Complete the Triangles Practice Set (p. 305-306)
• Read the section on Polygons (p. 306-308)
• Complete the Quadrilaterals and Other Polygons Practice Set (p. 308-311)
• Read the section on Circles (p. 311-314)
• Complete the Circles Practice Set (p. 315-317)
• Read the section on Multiple Figures (p. 317-319)
• Complete the Multiple Figures Practice Set (p. 319-321)
• Read the section on Solids (p. 321-324)
• Complete the Solids Practice Set (p. 324-326)

Note: I have the 2009-10 edition, so page numbers might be different.

I have 2 days to finish this. I will go through the theory section to see if I've missed out anything. If yes, I will make a FC for it. Then I will do the practice sets. :-)

A Love Triangle

Finished Triangles yesterday. :-)

Which translates into, Geometry theory is complete!

This morning, I stared going through my Geo FCs. Want to make sure all the concepts and formulae are drilled into my head. Will practice some geo questions after that, cos it's always fun to be able to answer questions once you know your theory!!!

Yey! Very happy today!!! :-)

Day 28

Here is the PR Assessment Summary:

QUANT

Category	R	W	U	% Correct
Problem Solving	19	3	0	86%
PS Math Definitions	1	0	0	100%
PS Frac/Dec/Percent	3	0	0	100%
PS Exponents/Roots	1	0	0	100%
PS Ratios/Proprtns	2	0	0	100%
PS Avgs/Rates/Stats	2	0	0	100%
PS Probablility	0	1	0	0%
PS Plugging In	5	1	0	83%
PS PITA	2	1	0	67%
PS Estimation	1	0	0	100%
PS Geometry	2	0	0	100%
Data Sufficiency	12	3	0	80%
DS Math Definitions	2	1	0	67%
DS Frac/Dec/Percent	1	0	0	100%
DS Ratios/Proprtns	1	1	0	50%
DS Avgs/Rates/Stats	1	0	0	100%
DS Eqtns/Inequals	2	1	0	67%
DS Simul Eqtns	1	0	0	100%
DS Geometry	1	0	0	100%
DS Yes/No	3	0	0	100%

Most of my Math errors were caused by not reading the question/statements/answer choices carefully! I used the wrong formula in one place (silly!!! I knew the right formula but blanked out during the exam), and there was one concept error. I didn't realise that if you try to put a cylinder in a cuboid, the maximum diameter of the cylinder can NEVER be equivalent to the longest side of the cuboid. This is because even the floor of the cuboid would have one side which is NOT the longest side. And therefore, the diameter of that cylinder can only be equal to the second longest side of the cuboid, and not more than that (ADD THIS TO FCs!).
There is one Math question I couldn't solve even on my second try, and when I checked the answer, I still didn't get it! I don't understand the solution, and am probably understanding the question wrong. I'll add it here later. I've asked a friend to look into it and let me know.

VERBAL

Category	R	W	U	% Correct
Sentence Corr.	13	2	0	87%
Red Pencil Fever	1	0	0	100%
Idiom	3	1	0	75%
Verb Tense	2	0	0	100%
Subject/Verb Agreement	1	0	0	100%
Pronouns	1	0	0	100%
Parallel Construction	4	0	0	100%
Quantity Words	1	0	0	100%
Misc	0	1	0	0%
Arguments	11	1	0	92%
Weaken	3	1	0	75%
Assumption	5	0	0	100%
Resolve/Explain	1	0	0	100%
Strengthen	2	0	0	100%
Reading Comp.	9	5	0	64%
RC General	2	1	0	67%
RC Specific	5	4	0	56%
RC Reasoning	2	0	0	100%

I started reviewing the Verbal part here in office, but got stuck with the solution of the first wrong answer itself! It's an SC question, and my God! What solutions! I may be good at Verbal and may assume I write grammatically correct sentences, but I am completely unaware of technical explanations for why one answer is better than another! I've always been dependent on what sounds right to my ear, because I thought my extensive reading would be of help. Apparently, not on the GMAT! Hmmm...thinking of picking up MGMAT SC book. Anyway, I'll add to this when I get back home.