2 tough math problems

Discus: SAT/ACT Tests and Test Preparation: May 2003 Archive: 2 tough math problems
 By Ace1 (Ace1) on Thursday, May 15, 2003 - 12:16 am: Edit

GRID IN #24
juan, eunice and mina are driving to work at the same office. Juan's driving time is half as long as Eunice's driving time and mina's driving time is 40 minutes longer than Eunice's driving time. If they all arrive at the same time and their total combined driving time is 120 min, what fraction of mina's driving time remains when eunice starts driving???

QUANT COMP#15
in triangle RST, the length of RS is 5, the length of RT is 10 and the measure of angle S is 90 degrees
column A= the measure of angle R
column B= 60 degrees

see if you guys can figure these out.

 By Ndhawk (Ndhawk) on Thursday, May 15, 2003 - 12:44 am: Edit

you do e = 2j and m = 2j + 40, so you have j + 2j + 2j + 40 = 120, 5j = 80, j = 16, so e starts driving with 32 minutes left, so m has 32/72, simplify to get 4/9

qc:
st will be the square root of 75, which is 5 times the square root of 3, this is a 30-60-90 triangle, angle r is the 60 angle, so they are equivalent