Answer:
4 liters of 5% and 16 liters of 17.5%
Step-by-step explanation:
Let quantity of 5% be x liters and of 17.5% be y liters
x+y=20 hence y=20-x
Introducing percentages
0.05x+0.175(20-x)=0.15*20
0.05x+3.5-0.175x=3
-0.125x=-0.5
Therefore, y=20-x=20-4=16
You need 4 liters of 5% and 16 liters of 17.5% to achieve 20 liters of 15% acid solution
Answer:
£12 per hour
Step-by-step explanation:
7 × 5 = 35 hours
35 h : 420
1 h : x
x = 420×1 / 35
= £12 per hour
You divide -15 on both sides to keep the x alone
-240/ -15=16
A negative divided by a negative is a positive so x=16
Answer:
19.53
Step-by-step explanation:
First let's find the new price of the backpack:
40% of 29.99 is
29.99 * 0.40 = 11.99
So the new price of the backpack is
29.99 - 11.99 = 18.00
Now let's find the price with tax
8.5% of 18.00 is
18.00 * 0.085 = 1.53
So the cost of the backpack is
18.00 + 1.53 = $19.53
