You need 320 ml of a 65% alcohol solution. on hand, you have a 60% alcohol mixture. how much of the 60% alcohol mixture and pure alcohol will you need to obtain the desired solution?
you will need
ml of the 60% solution
and
ml of pure alcohol.

You will need

280 mL of the 60% solution

and  40 mL of pure alcohol.

Step-by-step explanation:

Let 'x' be the amount of 60% alcohol solution and y the amount of pure alcohol.

Therefore:

(0.6x + y)/320 = 0.65 ⇒ 0.6x + y = 208

x + y = 320

Solving the sistem of equations:

x = 280 and y = 40

Therefore, You will need

280 mL of the 60% solution

and  40 mL of pure alcohol.

answer: given that the roller coaster can accommodate 1600 riders per hour, thus the roller coaster can accomodate 1600 / 60 = 26.67 riders per minute.

given that there are 345 people in the line, the number of minutes it will take for the 345 persons to get into the roller coaster is given by 345 / 26.67 = 12.94 minutes.

therefore, it will take you 12.94 minutes to get to the front of the line.

step-by-step explanation: