Trex88
why isn't this method giving correct ans.?
let total employees = 100
let female employees = x
so male employees = 100-x
so acc. to question :
{50/100 x (100-x)} + {40/100 x x} = 42/100
this gives x = 49.58
Hi
Trex88 Thanks for your query.
Firstly, I want to appreciate your approach - it is crisp and direct and can save solution time. BUT while your approach was smart, you made a very careless mistake in executing it.
I’m calling it careless because looking at most of your solution, it doesn’t appear that you don’t have the core skill needed. Let me dive right in!
Here’s the left-hand side of your equation (it is perfect!):
- 50% of male employees + 40% of female employees
- = {50/100 × (100 – x)} + {40/100 × (x)}.
Now, here is the right-hand side of your equation:
Does it look off to you? It has something very important just completely missing!
Well, you missed mentioning 42% of
WHAT! Specifically, you did not write the
100 on the right-hand side. You could have avoided this if you were very careful while translating the question: it said, “42%
of all the employees are at least 35 years old.”
- Thus, the correct expression on the right-hand side should be {(42/100) × 100}. [NOT just 42/100].
Try solving the correct equation again. You will get
x = 80. And so, the final
required fraction = x/100 = 80/100 = 4/5.
And that’s it! It was just a blink that made you go wrong despite having such a direct approach.
Hope this helps!
Best,
Aditi Gupta,
Quant expert,
e-GMAT