Answer:
r = 7
Step-by-step explanation:

Answer:
1 : 4
Step-by-step explanation:
Let x represent the amount of 30% solution for 1 unit of 5% solution. Then the amount of acid in the mix is ...
0.30x + 0.05·1 = 0.10·(x +1)
0.30x + 0.05 = 0.10x + 0.10 . . . . eliminate parentheses
0.20x = 0.05 . . . . . . . . . . . . . . . . subtract 0.05+0.10x
x = 0.05/0.20 = 1/4
That is, the ratio x : 1 is 1 : 4.
I believe it is answer A...He pays 485 originally and then 25 to his brother ever hour so 485+75 is 560 making A the answer.
Answer:
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
Step-by-step explanation: