Answer:
Mrs. Stern washed more
laundry still needs to be washed.
Step-by-step explanation:
Total amount of laundry: 


of the laundry still needs to be done.
Mrs. Stern washed
of the laundry.
Her son washed
of the laundry.
Mrs. Stern washed more laundry than her son.
Let's first find out their factors.
90's factors are :

190's factors are :

The common factors of 90 and 190 are :
1,2,5 and 10.
The greatest one among these is, 10. So the greatest factor of 90 and 190 is 10.
Answer:
10
Step-by-step explanation: