Answer:
116
Step-by-step explanation:
you can use variables
a+b=110
a+c=112
a+d=113
b+c=118
b+d=121
add up the weights and you get 574 kg (you need to find c+d)
3a+3b+2c+2d=574
a+b+c+d = 230 as given then you multiply by 3 so you can cancel out 3a and 3b and subtract 690-574 because we multiplied by 3
you are left with c+d=116
