A little more long winded but may be easier for child to understand.

Not long winded at all, Caleb. If the students know how to draw a good model like you did, they can solve this problem easily. Thank you.

Thank you

We are glad to help. Regards

Thanks Mr Yeo.

Thanks

Raymond, where u get 81 n 16?

Not 81... 😭 I wrote pi (8)^2 1/2 x 16 x 16 is the area of the rhombus

Raymond 3D eyes transformation!! 👍👍 I still need to do the long winded way.

Mr Yeo, can do your long winded way?

Attached wrong pic.

Yeo See Yeong, pls get a new calculator. Your pi gives you an error of 0.03 cm^2... 😭

Thanks for the correction Raymond Ng. My calculator works well. It's user problem. I use 3.142 instead of the pi in calculator. Raymond's answer is correct at 73.06 cm^2

Raymond, by he side of the rhombus 16,how did you get it?

So far I noticed 3 persons who are very good in reading and solving these type of questions. Raymond, Xavier and shu hao. Am sure there are many more who are crouching tiger hidden dragon. Loads to learn from you guys.

The rhombus is a square, diagonals of length 16cm

If you're not comfortable with rhombus formula, just use 2 x area of triangles ☺

No. They add up to 4 small squares... 😛

Poh Poh, so how's your DSA?

Mister Yeo, you made me blush. Thank you, 您太抬举我了. In all seriousness, once you learn what to look for you can be as good, if not better, than any one of us. 我看重您,加油!

Your child had either made a mistake while copying the solution, or the teacher had given one with the mistake. (a) the solution should read as follow : 1/3 × 63 × 60 × 15 = 18900

The question states that the final water level in Tank Y is 1/3 × 63 cm = 21 cm. That must also be the height of the water level in Tank X at the end. Hence the water remaining in Tank X is18900 cubic cm