Question

How much pure alcohol must a nurse add to 10 cm3 of a 60% alcohol solution to strengthen it to a 90% solution?

Answer 1

Answer:

30cm3

Step-by-step explanation:

she already has: 60%:10

pure ones: 100%:x

need:90%:10+x

so u can get this eq:

6+x=9+0.9

0.1x=3

x=30

Hope it'll help, Good night!

Answer 2

Answer:

30cm³

Step-by-step explanation:

6 + x = 9 + 0.9

0.1x = 3

0.1x ÷ 0.1 = 3 ÷ 0.1

x = 30