At this time, the sum of water and container weight is 65438+ raw water (before the first pouring) and container weight, that is, 5/2 of raw water1+container weight =65438+ 0/3 of raw water+0/3 of container weight, so it can be calculated that raw water weight =7 times container weight.
Pour out 2/7 of the water, and the remaining water and container weigh 7.2kg, that is, 5/7 of the original water+container weight =7.2kg.
Substituting the original weight relationship between water and container, the container weight = 1.2 kg, and the original water weight =8.4 kg.
Arithmetic solution formula:
( 1-2/7)×( 1-2/3)=5/2 1
( 1/3-5/2 1)÷( 1- 1/3)= 1/7
7.2÷( 1/7+5/7)=8.4
Equation solving formula:
Let the raw water be x kg and the container mass be y kg.
( 1-2/7)x+y=7.2
( 1-2/7)( 1-2/3)x+y =(x+y)/3
x= 1.2，y=8.4