Thank you that makes sense. I'll have to increase my base understanding on common math formulas for the gmat it seems
Hi ItsMeHudd,Good question. The
q isn't pulled out of nowhere; it's just a
name the solutions gave to the
quotient - the whole-number part of a division.
Whenever you divide one positive integer by another, you can always write:
dividend = divisor × quotient + remainderFor this question that's:
k = n·q + 11Here
q is simply "how many whole times n goes into k." Bunuel introduced the letter
q to stand for that number before we know its value. Then dividing both sides by n gives:
k/n = q + 11/nNow compare that to what you're told:
k/n = 81.2 = 81 + 0.2.
- The
whole-number part,
81, must be
q (the quotient).
- The
leftover fraction,
0.2, must be the
11/n piece.
Thereforeq = 81, and
11/n = 0.2, which gives
n = 55.
A tiny concrete checkTake something you can see instantly:
17 ÷ 5 = 3.4.
- The quotient is the whole part:
3 - that's your
q.
-
5 ×
3 =
15, and
17 -
15 =
2, the remainder.
- So
17 = 5·3 + 2, and
17/5 = 3 + 2/5 = 3.4. ✓
Notice how the whole number (
3) is the quotient and the decimal (
0.4 = 2/5) is remainder-over-divisor. That's exactly the same split used with
81.2 in this problem -
q is just the label for that whole-number quotient.
Answer: C