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

Redeem

Que: The number of cars this year decreased by 10% compared to last year. The number of mobiles this year ....

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

Que: The number of cars this year decreased by 10% compared to last year. The number of mobiles this year ....

by Max@Math Revolution » Wed Mar 10, 2021 9:03 pm

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Que: The number of cars this year decreased by 10% compared to last year. The number of mobiles this year has increased by 12% compared to last year. If the total number of cars and mobiles this year increased by 5% compared to last year, what was the ratio of the number of cars to the number of mobiles last year?

A. 1:2
B. 15:7
C. 9:11
D. 11:9
E. 7:15
Top
Source: — Problem Solving |
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

Re: Que: The number of cars this year decreased by 10% compared to last year. The number of mobiles this year ....

by Max@Math Revolution » Sat Mar 13, 2021 9:24 pm
Solution: Now let's solve this PS question using IVY Approach.

IVY Approach -> IVY Approach 3-2: 100c = Cars ; 100m= Mobiles

=> Percentage question ->100 -> c = cars ; m = mobiles

=> This year cars = 90% of 100c = 90c \(\left(10\%\ decrease\right)\)

=> This year mobiles = 112% of 100m = 112m \(\left(12\%\ increase\right)\)

=> Total Vehicles this year: 105% of(100c + 100m) = 105c + 105m \(\left(2\%\ increase\right)\)

=> 90c + 112m = 105c + 105m

=> 112m – 105m = 105c – 90c

=>7m = 15c

=> c = \(\frac{7}{15}\)m

=> ∴ 100c : 100m =c :m=\(\frac{7}{15}\) m: m = 7 :15

Therefore, E is the correct answer.

Answer E
Top
Post new topic Post Reply
• Page 1 of 1