This is false, since moving the decimal point to the left makes the number smaller. Therefore, the number on the exponent should be negative.
Answer:
70
Step-by-step explanation:
140=2x
divide by 2
x=70
Answer:
6
Step-by-step explanation:
450/75= 6 hours
x = liters of 20% solution
Mixing the 20% solution with the 60 L of 90% solution gives a new mixture with volume (x + 60) L. Each L of the 20% solution contributes 0.2 L of alcohol and thus a total of 0.2x L of alcohol, while the 60 L of 90% solution contributes 54 L of alcohol.
We want the concentration of the new mixture to be 80%, so we require

Solve for x:



So you will need 30 L of the 20% solution.