Post your question in the Comment section below, and a GRE expert will answer it as fast as humanly possible.
- Video Course
- Video Course Overview
- General GRE Info and Strategies - 7 videos (free)
- Quantitative Comparison - 7 videos (free)
- Arithmetic - 42 videos
- Powers and Roots - 43 videos
- Algebra and Equation Solving - 78 videos
- Word Problems - 54 videos
- Geometry - 48 videos
- Integer Properties - 34 videos
- Statistics - 28 videos
- Counting - 27 videos
- Probability - 25 videos
- Data Interpretation - 24 videos
- Analytical Writing - 9 videos (free)
- Sentence Equivalence - 39 videos (free)
- Text Completion - 51 videos
- Reading Comprehension - 16 videos
- Study Guide
- Philosophy
- Office Hours
- Extras
- Prices
Comment on Tips for the Input-Output Approach
Hey, I had fun using an
Try plugging in a = 0 and b =
Try plugging in a = 0 and b = 30 and see which answer choices yield the required output of 90 cents. PRO TIP: Using super convenient numbers like this will often yield more than one answer choice that works (the test-makers often penalize you from using easy numbers like 0), which means you'll have take the remaining answer choices and plug in different values.
Sir i took my investment to
from Wednesday to Thursday = 5% increase
From Thursday to Friday = 7% increase
I randomly selected 5% and 7%
Therefore
Thursday => 5% increase means = 105% or 1.05
=> 1.05*100 = 105$
Friday => 7% increase means 107% or 1.07
=> 1.07*105 = $112.35
percentage change is 112.35 - 100 = 12.35.
none of my options yield the result 12.35
Option A gives 12%/100
Option B gives 0.120035 or 12.0035%
Option c gives 12%
option D gives 12.0035%
option E gives 0.0011985 or 0.11%
what am i doing wrong?
ohhh okay i got.... My
Please can you also share the
I believe you're referring to
I believe you're referring to the question that starts around 6:25 in the video.
It's a killer!!!
Let W = value of portfolio on Wednesday
So (1 + x/100)W = value of portfolio on Thursday
And (1 + y/100)(1 + x/100)W = value of portfolio on Friday
Percent increase = 100(new - old)/old
So, percent increase = 100[(1 + y/100)(1 + x/100)W - W]/W
This expression does not match any of the answer choices.
So, we need to rewrite the expression.
Take: 100[(1 + y/100)(1 + x/100)W - W]/W
Divide top and bottom by W to get: 100[(1 + y/100)(1 + x/100) - 1]/1
Expand to get: (100)(1 + y/100)(1 + x/100) - 100]/1
Aside: (100)(1 + y/100)= 100 + y
So, we can write: [(100 + y)(1 + x/100) - 100]/1
Multiply top and bottom of the fraction by 100 to get: [(100 + y)(100 + x) - 100²]/100
Rewrite as: (100 + y)(100 + x)/100 - 100²/100
Simplify: (100 + y)(100 + x)/100 - 100
Answer: B
Does that help?
Cheers,
Brent
Isn't the percent increase
I'm not sure what question
I'm not sure what question you're referring to, but your calculations are correct.
If some value increases from 150 to 180, then the...
...percent increase = [(180-150)/150](100)
= [30/150](100)
= [1/5](100)
= 100/5
= 20%
For more on percent increase, watch: https://www.greenlighttestprep.com/module/gre-arithmetic/video/1083
Cheers,
Brent
No answer was given for the
The correct answer (B) is
The correct answer (B) is displayed at 5:15 in the above video.