Answer How many liters of a 20% acid solution should be mixed with 30 liters of 50% acid solution in order to obtain a 40% solution. ... x=15 liters 15*(.20 pure acid)=3 liters 30*(.50 pure acid)=15 liters That is 18 liters pure acid That is 45 liters solution *0.45 pure acid=18 liters.
Step-by-step explanation:
Answer:
The value of x is
hours.
Step-by-step explanation:
Machine A = 5 hours
Machine B = x hours
Machine A and B = 2 hours
Using the formula: 
where:
T is the time spend by both machine
A is the time spend by machine A
B is the time spend by machine B

Let multiply the entire problem by the common denominator (5B)

2x + 10 = 5x
Collect the like terms
10 = 5x - 2x
10 = 3x
3x = 10
Divide both side by the coefficient of x (3)

hours.
Therefore, Machine B will fill the same lot in
hours.
Answer: 1232
Step-by-step explanation: ( 8x10 -3) x(2x10 -4)
( 8x10 -3) = 77
(2x10 -4) = 16
77 x 16 = 1232
Answer = 1232
Answer:
35 red marbles
Step-by-step explanation:
So we can put the different color marbles in a ratio. So 7:2:11. If we add all of those up we get 20. We do 100/20 to get 5. Each number in the ratio is equivalent to 5 marbles. Then we do 7*5 to get 35. We can check our work by doing, (7*5) + (2*5) + (11*5) = 100. And it does equal 100 so the answer is correct.