Question 1055454
 a farmer has 6 different size containers : 5, 9, 12 , 23,and 45 liters . 
 he has filled some of these containers with sunflower oil and some others with olive oil . 
 he has one empty container and the total amount of the sunflower oil in the container is 4 times the total amount of olive oil in the containers.
 what is the volume of the empty container? 
:
The total amt is a multiple of 5. 1 unit of sunflower + 4 units of Olive
We can eliminate 5 and 45.
Find the two out of the remaining three which add up to a multiple of 5; 12+23 = 35
That leaves the 9 liter container left over as empty