How many gallons of a 42% salt solution do we need to mix with 98 gallons of a 20% salt solution so that the resulting mixture is a 28% salt solution ?

52

Step-by-step explanation:

98 gallons of a 20 percent salt solution results in 20/100 * 98 = 19.6 gallons of salt.

Let's say we need x gallons of the 42% salt solution.

To make sure that the resulting mixture has 28% salt, we need to have the total salt divided by the total amount of gallons.

We have 98 total gallons in the first solution, and x total gallons in the second solution. We have 19.6 gallons of salt in the first solution and 42% of x gallons in the second solution:

Cross-multiplying, we have

Expanding, we have

Subtracting 1960 from both sides, and then subtracting 28x from both sides gets us

Dividing by 14 from both sides gets us

x=52

step-by-step explanation:

the true ones are a b and d

answer: the four apples you took away.

step-by-step explanation: