OG 12, Q 166 (%)

rahul.s wrote:During a certain season, a team won 80 percent of its first 100 games and 50 percent of its remaining games. If the team won 70 percent of its games for the entire season, what was the total number of games that the team played?

(A) 180
(B) 170
(C) 156
(D) 150
(E) 105

OA: D

i got the right answer but i wanted to know whether my approach was right since i'm quite weak with framing equations.

let x = remaining games (total - 100)
so, 80 + 50x/100 = (70/100) * (x + 100)
(8000 + 50x)/100 = (70x + 7000)/100
8000 - 7000 = 70x - 50x
1000 = 20x
x = 50
so total no. of games = 100 + 50 = 150

thoughts?

ajith wrote:I would have done the same. Well done

varundaga05 wrote:I think it is a very length approach.

Instead if we go by putting values it is less time consuming.

Example
========

105 * .70 will give fractions so we skip this choice
150*.70 = 105

Now 100 gives 80 and remaining 150 - 100 = 50 gives 25

i.e. 80 + 25 = 105 which is matching our result of 150 *.75.

Its much easier