Question

its was stella birthday.her father bought a cake.stella gave each of her 7friends one-tenth of the cake.what portion of the cake remain.

Answer 1

total pieces of  the cake = 10 /10 
distributed pieces of the cake = 7 / 10
therefore remaining part of the cake,
10 / 10 - 7 /1 0
= 3 / 10
therefore 3 / 10 of the total cake will be left out...
      i hope that this will help u...........................^_^

Answer 2

the complete cake is a whole
no. of parts = 10/10
no. of parts distributed=7/10
no.of parts remaining=10/10-7/10=3/10