GNF Final Interview


I was sitting on the chair, quite bewildered to what is happening around me. The japanese manager was laughing with all his might. Am I supposed to be humiliated and cry or burst out in anger like a person whose ego was hurt? I felt angry at the moment but ... I would not do so. Numbness took over me but I remained my composure. I was polite and still all smiles. It was over. I offered a handshake to the manager and left. The HR Head told me to wait for the call as long as tomorrow morning. I surrendered my ID to the guard, get my things, walked a few distance. After a few paces, stupidity took over me and hurtful feelings start to rise up. I eventually let my guard down and cried...

These were the last scenes during my final interview today at GNF Philippines. To give you an overview how I get there, well here's the story. I applied at GNF last January 19 but was called almost a month later to take the test. I passed the exam, have the initial interview. Last Tuesday, they called me to have my panel interview on Wedenesday. They called again, 30 min. after the panel interview and told me I passed and so I was here, 3:00 for the Final Interview.

I was given a problem. It was a chemistry-algebra related problem about Mixtures. Well here is the problem:

A tank operating at 10 cu.m has a concentration of 50g/L. Suddenly the concentration suddenly shoots to 60 g/L. As a production operator, how will you solve this problem so that the concentration will remain 50 g/L?

The problem was vague so I asked the japanese manager who interviewed me yesterday what the condition was. I asked if the tank is full and he answered no. The tank has a capacity of 20 cu. m.

To give you a general perspective how to approach this problem, there are two possible situations:
A solution is composed of a solute (salt) and a solvent (water).
a) If the solution reaches 60 g/L. It is possible that an additional solute has been mixed with the solution that's why the concentration increased. or...
b) If the solution reached 60g/L. It is a possible that some solvent has dried up or has evaporated thats why the concentration of the solute increased.

I first considered situation a) and I got my solution on the white board but as soon as I arrived at my answer, I suddenly thought that the operating volume should not exceed 10 cu. m and so it is possible that b) situation has happened. So, I erased my answer and solved again.

Here's the calculation:

Let x = the amount of solvent decreased

(10 - x)60 = 10(50)
600 - 60x = 500
-60x = -100
x = 1.667 or 1 2/3 cu. m


By getting this solution, It means that a total amount of 1.667 cu.m was lost, that is why the concentration increased to 60 g/L. To get on with the story, I explained my solution to my interviewers. I made sure I have been clear with my explanation but the manager could not understand me. He told me to explain my solution all over again. I was asked if I knew how to get the concentration and I did. He was still confused so I solved the equation his way. I think, he was irked in the process because he too himself must have been confused with what I've been doing and I was also confused with to where I'm getting at.

However, he first let me solve the total amount of solute using 10 cu. m of water with 60 g/L concentration. It was 600, then he let me add 1.667 to 10 cu. m. I should have realized by now that he was considering situation a), right? But I thought nothing of it and there I was following his orders. He let me divide 600 by 1.667. I arrived at 51.4 g/L. I assumed that this is just a tolerant error with the computation. The answer expected was 50 g/L. I could not think of any other way, so I just justified my solution. I told him, that this was just an error in computation since he let me use 1.67 instead of the exact 1 2/3. I have no idea that the correct situation is a) as much as I believed that b) situation is correct in my opinion. To my amzement and shock, he laughed, he laughed and laughed after all the "pasirko-sirko" explanations I made. Maybe he found me amusing or just plain pathetic! Well that was the situation I've told you earlier...
Near the gate, I rushed on my calculator to solve, only to find out that it should have been 2 and not 1.667. My ego was hurt, finding out that I, as a tutor before was never wrong! I'm supposed to be right because my tutees expect me to be right. And now, a simple mixture problem whose problem is so common like the ones I see as examples during my stay in Ateneo or the ones I solve during my review in Excel... and I got it wrong! What a shame! A very unbearable shame! If I were a Japanese, I would have killed myself. I felt really stupid and I cried, really cried my heart out for having my ego hurt.

After I get myself together, that's the time I found out that it was a) situation we've been tackling all along. And then I felt stupid why I cried. It's not worth crying after all. I was not wrong. If my case was followed, I was right. But, well... it was the other situation anyway and I can't do anything about it now.

Anyway, here is the correct solution:


let x = amount of solvent added.

(100 + x)50 = 10(60)
500 + 50x = 600
50x = 100
x = 2 cu. m


You have to add 2 L of solvent so that the concentration will decrease back to 50 g/L. I thought, the solution is not to exceed 10 cu. m that's why I considered situation b). Well you see, it's very plain simple. I should have asked him what the condition was.

Well, as a final word, situation like these have to happen in our lives. God is teaching me to be humble and accept my mistakes. It is my first intimate experience to learn this in a hard way. Although, in my heart I'm still insisting that I should have been right but fighting it was a way to learn and move on. God has the best plans for me and I trust it. And thinking about if I will still get the job after that, I still have tomorrow to find out. Life is STILL beautiful and thank God for it.