How many liters of water containing 7 grams of salt per liter must be combined with x liters of water which contains y grams [y is less than 2] of salt per liter to yield a solution with 2 grams of salt per liter.

Step-by-step explanation:

Let l litre of 7 grams of salt per litre is combined with x litres of water which contains y grams of salt per litre to yield a solution with 2 grams of salt per litre.

Thus,

Salt in l litre + salt in x litre = salt in resultant mixture

7l + xy = 2(l +x)

7l + xy = 2l + 2x

7l - 2l = 2x - xy

5l = x(2-y)

Hence, litres of 7 gram of salt per litre is mixed.

percentage - 25%

probability - 0.25

we know,

total amount of students in class = 20

total boys = 10

total girls = 10

no of girls who wear glasses = 10/2 = 5

probability of choosing a girl with glasses is =

number of girls wearing glasses/total number of students in the class = 5/20

thus, percentage of selecting a girl wearing glasses will be

= 5/20 × 100

= 5 × 5

25%

therefore,

probability will be 0.25

happy to

pls mark as brainliest

no he doesnt because "-16' is negatiive

step-by-step explanation: