Question

there are 10 pieces of pizza Brian ate one tenth of the pizza for dinner he ate four fifth of the pizza for bed time snack how much pizza is left

Answer 1

only one tenth of pizza is left . as
pizza left=1-(4/5+1/10)
               =1-9/10
                =1/10

Answer 2

1/10
He ate (1/10)+(8/10)=9/10
Left over 1/10 piece