UTM- Before and After Concept

Dear Mr Sunny Tan,

May I enquire if unit transfer method can be applied to solve the following problem. If yes, please show me.
Tan X, Y and Z each contained some water. Tank X contains 3 times as much water as Tank Y. After 15% of the water in Tank X and 15% of Tank Y was poured in Tank Z, Tank Z had 30% more than before. If Tank Z had 104 litres of water, how many litres of water had Tank X at first ?

Thank you

Yours sincerely,

Danielle Teo
(your student)

From the Desk of Sunny Tan........