Question

your friend drinks 2/3 of a bottle of water. You drink 5/7 of a bottle of water. FInd the difference of the amounts of water left in each bottle?

Answer 1

amount left in friends bottle = 1 - 2/3 = 1/3
amount left in your bottle = 1 - 5/7 = 2/7

Difference = 1/3 - 2/7 = 7/21 - 6/21 = 1/21 Answer

Answer 2

The difference of the amounts of water left in each bottle is 1/21 of the bottle.

Explanation:

Your friend drinks 2/3 of the bottle, which is a bottle divide in 3 parts and remove o take 2 parts, only rest 1 parts of the 3, that is the same to say tata remain 1/3 of the bottle of water. That also can be proved with the following calculation:

`1 - (2)/(3)= (1)/(1) - (2)/(3) = ((1*3) - (1*2))/(1*3) = (3-2)/(3) = (1)/(3)`

Your friend drinks 5/7 of the bottle, which is a bottle divide in 7 parts and remove o take 5 parts, only rest 2 parts of the 7, that is the same to say tata remain 2/7 of the bottle of water. That also can be proved with the following calculation:

`1 - (5)/(7)= (1)/(1)- (5)/(7) = ((1*7) - (1*5))/(1*7) = (7-5)/(7) = (2)/(7)`

Finally we have to find the difference between the two remains of the bottle, that can be made by a simple subtraction:

`(1)/(3)- (2)/(7) = ((1*7) - (3*2))/(3*7) = (7-6)/(21) = (1)/(21)`

Then, the difference of the amounts of water left in each bottle is 1/21 of the bottle.