In 1990, 75% of all high school seniors had jobs. In 2010, 40% of all seniors had jobs. If there were 50 more seniors in 2010 than 1990 and there were a total of 403 jobs between both years, how many seniors were there in 1990? How many seniors had jobs in 2010

There were 333 seniors in 1990

153 seniors had jobs in 2010.

Step-by-step explanation:

Let the number of high school seniors in 1990 = x

75% of x had jobs in 1990

In 2010 there were 50 more seniors. That is, the number of seniors is x+50.

40% of (x+50) had jobs in 2010.

Total number of jobs in both years = 403.

/[0.75 * x + 0.4 * (x + 50) = 403/]

/[0.75 * x + 0.4 * x + 20 = 403/]

=> / [1.15 * x = 403 - 20/]

=> / [1.15 * x = 383/]

=> / [x = 383/1.15/]

=> / [x = 333/]

Number of seniors having job in 2010 = 0.4 * (333 + 50) = 0.4 * 383 = 153.2 = 153 (approx)