Respuesta :

Answer:

168 minutes, or 2 hours, 48 minutes

Step-by-step explanation:

Set up a proportion and solve.

56 minutes is to 4 tires as 'x' minutes are to 12 tires

becomes

56/4 = x/12         solve for x...

[56(12)]/4 = x            (multiply both sides by 12 to get rid of the fraction)

672/4 = x                 (simplify  52(12) = 672)

168 = x                      (simplify 672/4 = 168)