|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
sanjna2023
02 Sep 2020, 07:38
Kudos
Bookmarks
08 Dec 2020, 11:29
Kudos
Bookmarks
OFFICIAL GMAT EXPLANATION
Algebra; Arithmetic First-degree equations; Percents
Let C96 and C97 represent revenues from car sales in 1996 and 1997, respectively, and let T96 and T97 represent revenues from truck sales in 1996 and 1997, respectively. A decrease of 11 percent in revenue from car sales from 1996 to 1997 can be represented as (1 − 0.11)C96 = C97, and a 7 percent increase in revenue from truck sales from 1996 to 1997 can be represented as (1 + 0.07)T96 = T97. An overall increase of 1 percent in revenue from car and truck sales from 1996 to 1997 can be represented as C97 + T97 = (1 + 0.01)(C96 + T96).
Then, by substitution of expressions for C97 and T97 that were derived above, (1 − 0.11)C96 + (1 + 0.07)T96 = (1 + 0.01)(C96 + T96)and so 0.89C96 + 1.07T96 = 1.01(C96 + T96) or 0.89C96 + 1.07T96 = 1.01C96 + 1.01T96. Then, combining like terms gives (1.07 − 1.01)T96 = (1.01 − 0.89)C96 or 0.06T96 = 0.12C96. Thus C96T96=0.060.12=12. The ratio of revenue from car sales in 1996 to revenue from truck sales in 1996 is 1:2.
Algebra; Arithmetic First-degree equations; Percents
Let C96 and C97 represent revenues from car sales in 1996 and 1997, respectively, and let T96 and T97 represent revenues from truck sales in 1996 and 1997, respectively. A decrease of 11 percent in revenue from car sales from 1996 to 1997 can be represented as (1 − 0.11)C96 = C97, and a 7 percent increase in revenue from truck sales from 1996 to 1997 can be represented as (1 + 0.07)T96 = T97. An overall increase of 1 percent in revenue from car and truck sales from 1996 to 1997 can be represented as C97 + T97 = (1 + 0.01)(C96 + T96).
Then, by substitution of expressions for C97 and T97 that were derived above, (1 − 0.11)C96 + (1 + 0.07)T96 = (1 + 0.01)(C96 + T96)and so 0.89C96 + 1.07T96 = 1.01(C96 + T96) or 0.89C96 + 1.07T96 = 1.01C96 + 1.01T96. Then, combining like terms gives (1.07 − 1.01)T96 = (1.01 − 0.89)C96 or 0.06T96 = 0.12C96. Thus C96T96=0.060.12=12. The ratio of revenue from car sales in 1996 to revenue from truck sales in 1996 is 1:2.
13 May 2022, 14:51
Kudos
Bookmarks
Bunuel
Ballpark.
If you don't understand the value of ballparking in order to work faster, to avoid mistakes, and to not need to memorize formulas, just scroll up in this thread for evidence. Ballparking is the single most important math concept on the GMAT.
Cars were DOWN 11%.
Trucks were UP 7%.
If we had an equal amount of each, we would have a net DOWN.
But the question tells us we have a net UP, so we need more trucks than cars.
Look at the answer choices. Eliminate C, D, and E.
Do we need a lot more trucks (answer choice A) or just baaarely more trucks (answer choice B)? We need a lot more trucks!
Answer choice A.
ThatDudeKnowsBallparking
