Hello,
Angles y and 3y+8 are supplementaries since the quadrilater is inscribed
y+3y+8=180
==>4y=172
==>y=43 (°)
Cf=cold faucet rate
hf=hot faucet rate
cf*18min=1 tub
(cf+hf)*8min=1 tub
cf+hf=1tub/8min
cf=1tub/18min
hf=(1/8-1/18)tubs per minute
hf=5/72
It takes 14.4 minutes.
Tu tia tenia 21 años de wear despues de 9 años de edad.