Answer:
Yes.
Explanation:
We have to first find how much of the whole cake (1) that they all ate.
Boris eats 1/5 of the cake.
Maziy eats 1/5 of the cake.
Sanjay and Silas eat 1/5 of the cake.
Jack also has 1/5 of the cake.
The total fraction of cake eaten was:
1/5 + 1/5 + 1/5 + 1/5 = 4/5
Therefore,the fraction of the cake left is:
1 - 4/5 = 1/5
Yes, there is cake left.