Given that 1490.59 = x, 1490.94 = y and xz = y6, then the value of z is close to:
Pipe A can fill a tank in 16 hours, pipe B can fill the same tank in 25 hours and pipe C can fill the same tank in 12 hours. The time taken by them to fill the same tank if they operate together is:
5 \( \frac{85}{223} \) hours
3 \( \frac{85}{223} \) hours
1 \( \frac{85}{223} \) hours
9 \( \frac{85}{223} \) hours