[DS][Sets] HSPA posts

[HSPA]

To receive a driver license, sixteen year-olds at Culliver High School have to pass both a written and a practical driving test. Everyone has to take the tests, and no one failed both tests. If 30% of the 16 year-olds who passed the written test did not pass the practical, how many sixteen year-olds at Culliver High School received their driver license?

(1) There are 188 sixteen year-olds at Culliver High School.

(2) 20% of the sixteen year-olds who passed the practical test failed the written test.

[force5]

we know if total who passed written were x then those who also passed practical are 0.7x (those who passed written and didn't pass practical are 0.3x

stmnt 1 says give total students. (insuff)
stmnt 2 gives if total who pass pract are y then those who failed written and passed pract are 0.2y and those who passed practical and passed written are 0.8y. still insufficient
combining. we can solve for x and y.

IMo-C