A scientist needs 10 liters of a 20% acid solution for an experiment, but she only has a 5% solution and a 40% solution. To the nearest tenth of a liter, about how many liters of the 5% and 40% solutions should she mix to get the solution she needs?

9514 1404 393

Step-by-step explanation:

Let x represent the number of liters of 40% solution in the mix. Then the total amount of acid in the mix is ...

  0.40x +0.05(10-x) = 0.20(10)

  0.35x +0.5 = 2.0

  0.35x = 1.5

  x = 1.5/0.35 ≈ 4.3 . . . . liters of 40% solution

  10-x = 10 -4.3 = 5.7 . . .liters of 5% solution

yes

step-by-step explanation:

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.