Percentage

[arpan_de]

The total fees of a school is 31000 bucks. A students pays, say, 16000 bucks as first installment. Suppose he leaves the school after 15 days. He is told that 20% of the total fees will be deducted. How much refund will he get? Here are the two methods - which one is correct?


Method I:
---------
31000 x 20% (of 31000) = 6200
16000 - 6200 = 9800 (is the refund he will get)


Method 2:
---------
31000 - 20% (of 31000) = 24800
24800 - 16000 = 8800 (is the refund he will get)

Which of the above 2 methods is correct & why? What is the difference between the two methods?

Thanks

 

[tkhunny]

Method 2 - Why are we subtracting ANYTHING from 31000?! We should be subtracting from what was paid!

 

[Ishuda]

The total fees of a school is 31000 bucks. A students pays, say, 16000 bucks as first installment. Suppose he leaves the school after 15 days. He is told that 20% of the total fees will be deducted from what. How much refund will he get? Here are the two methods - which one is correct?
...

If the deduction is from the total fees (see above in red) then neither is correct:

"20% of the total fees" = .2 * the total fees
"The total fees of a school is 31000 bucks" = .2 * 31000 = 6200
So $6200 will be returned from the total fees of $31000, meaning you owe $24800
$31000 - $6200 = $24800
You are good up to this point with Method 2. BUT
You have already paid $16000. So you still owe $8800.
$24800 - $16000 = $8800.
You don't get a refund!

If the deduction is from your down payment, then $6200 is subtracted from your down payment and Method 1 is correct.

Edit: Normally, if nothing else were indicated I would expect that what was meant was the deduction from the down payment and Method 1 would be correct. And, later, to fix a dumb arithmetic misteak.

 

[Ishuda]

WHO "made up" the 2nd method...makes no sense...

Yes it does if (1) the 20% reduction is off the amount of the total fees and (2) you assume a mistake was made in the final step, i.e.
24800 - 16000 = 8800 (is not the refund he will get, it is the amount still owed)

Edit: However, if you mean that the school is dumb for doing that, I might agree.