Răspuns :
a=98 m in prima zi
b=98+9=107 m in a doua zi
c=107+9=116 m in a treia zi
a+b+c=98+107+116=321 m a sapat in cele trei zile
b=98+9=107 m in a doua zi
c=107+9=116 m in a treia zi
a+b+c=98+107+116=321 m a sapat in cele trei zile
98m+9m=107m (in a 2 zi)
107m+9m=116m(in a 3 zi )
98m+107m+116m=205m+116m=321m (in total)
107m+9m=116m(in a 3 zi )
98m+107m+116m=205m+116m=321m (in total)