Thanks

May i know why use 45/2=22.5mins?
Is 45 referring to tank b height? why cannot use 60 instead?
I am having the same problem with this qn. Pls help. thank you.

appreciate anyone can help me with my above qn. thank u.

Yes 45cm is referring to the water level in tank B at first, 2cm is derived when we add the increase in height of tank A (1.5cm) in every 1 min plus the decrease in height of tank b (0.5cm) in every 1min. We want to find out in how many mins will the water level increase in tank A and the decrease in tank b adds up to the original 45cm water level at first.

Hope this helps to clarify, you can see the checking part at the bottom to prove that the ans is correct.

I assume 60cm height of tank A cannot be used because the max height of the water level to meet cannot be higher than 45?

Yup, have to use 45 cm as that is the height of the water level originally

thank u so much for your explanation.