Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

The cost of gasoline increases by 10%. How many percent must a driver cut back on their gas usage in order to maintain the same expenditure?


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

9 1 11 %  

b

9 1 10 %  

c

9 1 9 %  

d

None of the above 

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

Given that, the cost of gasoline increases by 10%.
We know that, Decrease in %= Decrease in quantity original quantity ×100    -(i)
Let the cost of 1unit gasoline usage be Rs ‘x’.
The new cost of 1 unit gasoline after the cost increases by 10% :
New cost of 1unit gasoline,
Rs x+10% x  
  Rs x+ 10x 100 Rs 100x+10x 100   Rs 110x 100  
New cost of 1 unit gasoline =Rs 11x 10  .
As mentioned in the question, we want to cut the usage such that expenditure remains same.
Rs 11x 10 =1 unit of gasoline Rs. 1= 10 11x  unit of gasoline Rs. x= 10 11x ×x units of gasoline Rs. x= 10 11  units of gasoline  
10 11  units of gasoline  can be consumed in order to maintain the expenditure.
Decrease in usage,
1 10 11 units 1 11 units   (ii)
Now, using (i) & (ii):
Reduction in usage:
Original usage = 1 unit.
Decrease in usage Original usage ×100 % 1/11 1 ×100 % 100 11 %   Reduction in usage =9 1 11 %  .
Hence, option 1 is correct.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring