Mrs quirk buys 1 quart of milk, Michael drinks 2/7quart of it. joel drinks 1/3 quart. how many quart are left

Total quantity of milk bought by Mrs Quirk = 1 quart

Quantity of milk Michael drank from it = 2/7 quart

Amount of milk drank by Joe from it = 1/3 quart.

So the total amount of milk drank by Michael and Joe = (2/7) + (1/3)

= (6 + 7) / 21

= 13/21 quart

Then

Amount of milk left = 1 - (13/21) quart

= (21 - 13) / 21

= 8/21 quart

So 8/21 quart of milk is left after Michael and Joe drank from the 1 quart bought by Mrs Quirk. I hope this is the answer you were looking for and the procedure of doing this problem is clear to you.