A parking lot charges its rental in the following way- first three

Question

A parking lot charges its rental in the following way- first three hour cost $5, every additional hour costs $3 until a total of eight hours and thereafter, every additional hour costs $4. Alternately, one can pay flat $20 beforehand for 12 hours, Kevin was not aware of the second option and parked his car for exactly 12 hours without making the upfront payment and thus, was charged the first way. How many dollars could Kevin have saved if he had been aware of the second option? 
 
A. 6 
 B. 10 
 C. 14 
 D. 16 
 E. 22

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Akriti_Khetawat · Answer

First way = 3*5+5*3+4*4 = $46.
Second way = Flat $20
Money that could have been saved = $46-$20 = $26.

This is not there in the options, where have I gone wrong?

Ribas · Answer

First 3 hours = 5 total, not 5 per hour.

So it's 5 + 3 * 5 + 4 * 4 = 36;

36 - 20 = 16, answer D.

7seven7 · Answer

They charge $5 for first 3 hours (not each)

So, its 5 + (5*3) + (4*4) = $36
So, saved 36 - 20 = $16 (Option D)

siya1998 · Answer

Shouldnt the charge be - 5 + 3*(8) + 4*(1) = 33 dollars. The question says until a total of 8 hours.

MartyMurray · Answer

Take another look at these parts:

first three hour  cost $5

every additional hour costs $3 until a  total  of eight hours

What role does the word "total" play in the meaning?

dolorquaerat · Answer

first three hours‘ fee is just 5,donot need to multiple3

siya1998 · Answer

Thanks for the response. At first, I interpreted 8 hours starting from the 4th hour, hence, got the incorrect answer. I have understood now; it's 8 hours starting from the 0th hour.

ManishaPrepMinds · Answer

Pricing breakdown: 
 
  First 3 hours: $5 total  
  Hours 4–8: 5 hours × $3 = $15  
  Hours 9–12: 4 hours × $4 = $16  
  Standard total = $5 + $15 + $16 = $36  
  Flat 12-hour option = $20  
  Savings = $36 − $20 = $16
   
 Common trap: 
 
  5 + 3×8 + 4×1 = 33 is incorrect because the first 3 hours are covered by the $5 flat block; the $3 rate applies only to hours 4–8.  
  Tip: In tiered pricing,  map  each rate to its exact hour range to  avoid double-counting.

A parking lot charges its rental in the following way- first three

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A parking lot charges its rental in the following way- first three

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