Question 161429
x*3x/(x+3x)=8
3x^2=8*4x
3x^2=32x
3x^2-32x=0
x(3x-32)=0
3x-32=0
3x=32
x=32/3 or 10.667 Andrew's time.
3x=3*10.66=32 John's time.
Proof:
10.667*32/(10.667+32)=8
341.333/42.667=8
8=8