This primary school problem below has proved too tough for me to crack. I have sought opinions from a lot of people, but we all end up hitting a dead end. A lot of people even concluded the problem in itself is wrong, but I know the answer lies there.

Nairaland's education section is my last resort now. All the eficos should please help with the answer accompanied by a detailed explanation. Thanks

Cc: fynestboi
Iamolusa