Answer:  
 
 
Explanation:
The part of sandwich Keisha took to the picnic=
 of whole sandwich
 of whole sandwich
The part of sandwich ate by family=
 of whole sandwich.
 of whole sandwich.
The part of sandwich Keisha bring back home=

 of the whole sandwich.
 of the whole sandwich.
Hence, Keisha bring back 
 part of whole sandwich.
 part of whole sandwich.