This is a Math question please read it below

Candis has an 11-liter can and a 5-liter. How can she measure out exactly 7 liters of water into a third unmarked container?

Let's call the 11 litre can A
Let's call the 5 litre can B
Let's call the unmarked container C

So we're starting with A = 11, B = 5 C = 0 (assuming both cans are full and the third unmarked container is empty).

Step 1.

Empty B into C, this gives us A = 11 B = 0 C = 5

Step 2.
Empty A into B, this gives us A = 6 B = 5 C = 5

Step 3.

Empty B into C

This gives us A = 6 B = 0 C = 10

Step 4.

Empty A into B

This gives us A = 1 B = 5 C = 10

Step 5.

Empty B into C

This gives us A = 1 B = 0 C = 15

Step 6.

Empty A into B

This gives us A = 0 B = 1 C = 15

Step 7.

Empty C into A

This gives us A = 11 B = 1 C = 4

Step 8.
Throw away contents of C so that it is lost.

This gives us A = 11 B = 1 C = 0

Step 9
Empty contents of A and B into C

This gives us A = 0 B = 0 C = 12

Step 10.

Empty contents of C into B

This gives us A = 0 B = 5 C = 7

Candis now has 7 litres in teh unmarked container.

Hope this helps.