Respuesta :

PhyCS
Since 75 minutes is 5 times of 15 minutes, she can finish in proportion 2*5 = 10 homework problems.
VenusRetrograde
Answer= 10 math problems

 2math problems      x math problems
______________=_______________
   15 minutes               75 minutes

cross multiply
15x=150
divide both sides by 15
x=10 math problems

Lena can finish 10 math problems in 75 minutes