emdadul28 wrote:If goods be purchased for 840 and one-fourth be sold at a loss of 20% at what gain percent should the remainder be sold so as to gain 20% on the whole transaction?
A. 30%
B. 33%
C. 33 1/3%
D. 35%
[ please help me to understand similar maths with a simple and short formula ]
THANKS IN ADVANCE.
We're missing an answer choice here, but...
Let's say there are 84 items purchased at $10 each. If we want a 20% profit, we'll need to make 20% of 840, or $168, so we'll require 840 + 168 = $1008 total revenue.
If 1/4 of the items were sold for a loss of 20%, each of these items was sold for $8. 1/4 of 84 is 21; these 21 items will bring in 8*21 = 168.
If we need total revenue of 1008, and we've brought in $168 with the first 21 items sold, that means the remaining 63 items will need to bring in another $840. So these items will need to go for 840/63, or 40/3 = 13 1/3 each.
If we purchased those items at $10 and sold them for 13 1/3, we'll make a profit of 3 1/3, or 33 1/3%. The answer is
C
