Question

1 point
4. A can contains a mixture of
two liquids A and B is the ratio 7
: :5. When 9 liters of mixture are
drawn off and the can is filled
with B, the ratio of A and B
becomes 7:9. How many liters
of liquid A were contained by
the can initially?
O 21
O 20
O 15
O 10​

Answer 1

Step-by-step explanation:

Suppose the can initially contains 7x and 5x of mixtures A and B respectively.

Quantity of A in mixture left =(7x−

12

7

×9) litres =(7x−

4

21

) litres.

Quantity of B in mixture left =(5x−

12

5

×9) litres =(5x−

4

15

) litres.

∴

(5x−

4

15

)+9

(7x−

4

21

)

=

9

7

⇒

20x+21

28x−21

=

9

7

⇒252x−189=140x+147

⇒112x=336

⇒x=3.

So, the can contained 21 litres of A.

Answer 2

Answer:

21 litres is the answer