Hi, why did we eliminate 27 from the answer choices?
What do you think would happen if 27 was the answer?
we boomed
it.
On a serious note, the question is basically testing this:
A. To Increase
a Number by y%

If a number is increased by 10 %, then it becomes 1.1 times of itself.

If a number is increased by 50 %, then it becomes 1.5 times of itself.
B. To Decrease
a Number by y%

If a number is decreased by 10 %, then it becomes 0.90 times of itself.

If a number is decreased by 20 %, then it becomes 0.80 times of itself.
Sure thing.
I was actually back solving this question and I was able to Boom off 42 and 75 because they were not divisible by 1.08 (0.9*1.2). However, 27 and 54 were so I kept both these answer choices.
Why did I mess this?
In question it is mentioned that :
 Step 1: Reduce by 10%
 Step 2: Increase by 20%
The choices given shown the employees after 20% increase (Means after Step 2).
So, first let’s get to step 1) :
we do this by dividing
every answer choice by 1.2
A) 27 / 1.2 = 22.5
B)42 / 1.2 = 35
C)54 / 1.2 = 45
D)75 / 1.2 = 62.5
Remove the choices which are do not result in an integer! (can’t fired .3 of a person or hire .5 of a person for example )
A) \cancel{27 / 1.2 = 22.5}
B)42 / 1.2 = 35
C)54 / 1.2 = 45
D)\cancel{75 / 1.2 = 62.5}
Now, let’s divide this by .9
to get original number of employees :
B)35 / 0.9 = 38.88
C)45 / 0.9 = 50
Noted.
Should we always do such problems step by step? I was just taking the high road here by trying to divide in 1 go.
I mean there is no absolute rule about it ! Depends on problem to problem ; I personally like the stepbystep way as I don’t wanna waste time while rechecking / resolving conversion problems like this and Incase I do get stuck then I know exactly at what step I was stuck when I come back to it while rechecking.
Noted, thank you.