Answer:
Ellen have left 56 glasses to wash.
Step-by-step explanation:
Given that:
Number of glasses to be washed = 175
Percentage of glasses Ellen washed = 68%
Number of glasses Ellen washed = 
Number of glasses Ellen washed = 119
Number of glasses left = Total glasses - Number of glasses washed
Number of glasses left = 175 - 119 = 56
Hence,
Ellen have left 56 glasses to wash.