If p is a price in whole cents, which of the following could NOT be th

Question

If p is a price in whole cents, which of the following could NOT be the result of increasing p by 20%?

A. $1.20
B. $1.25
C. $1.38
D. $1.80
E. $2.52

pushpitkc · Answer

In order to check which of the following could NOT be got by increasing p by 20%, we need to divide
the answer options by 1.2 and if we don't end up with a whole number - that is our answer!

Evaluating answer options

A. $1.20/1.2 = 1
B. $1.25/1.2 = 1.0416 (This isin't a whole number)
C. $1.38/1.2 = 1.15
D. $1.80/1.2 = 1.5
E. $2.52/1.2 = 2.1  (Option B)

GMATBusters · Answer

pushpitkc , nice solution.

20 % increase = 100+20 = 120% = 1.2 times the original value.

We can convert the dollars to cents to make decimal part look clear.
 1 dollar = 100 cents

Finding original value of p from the options provided,  we will try to find the option which gives non-integer value.
 
A. 120/1.2 = 100
B. 125/1.2 =  104.1... (This is not a whole number) 
C. 138/1.2 = 115
D. 180/1.2 = 150
E. 252/1.2 = 210

Hence Answer = B

VaCeFe · Answer

The final price is equal to 
p + 0,20 p = 1,2 p = 12 * 10^-1 * p = 3 * 4 * 10 ^-1 * p . 
This means the number has to be divisible by 3 and 4. Testing if the answer is divisible by 3 we can find quicker the right option. 
Option B (1,25 = 125 * 10 ^-1) is not divisible by 3.

ScottTargetTestPrep · Answer

Solution:
 
Notice that $1.25, or 125 cents, is the only odd number of cents of the answer choices, so we will guess that $1.25 couldn’t be the result of increasing p by 20%. In other words, if p is increased by 20% and the result is $1.25, p couldn’t be a whole number of cents. Let’s show that this is indeed the case.

p x 1.2 = 125

p = 104.167

We see that 104.167 is not a whole number.

Answer: B

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If p is a price in whole cents, which of the following could NOT be th

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If p is a price in whole cents, which of the following could NOT be th

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