Formula for an algebra question

Question

How many ounces of a

1313​%

alcohol solution must be mixed with

33

ounces of a

2020​%

alcohol solution to make a

1616​%

alcohol​ solution

Answer 1

0.13x + 0.2*33 = (x+33)*0.16

0.13x + 6.6 = 0.16x + 5.28

6.6 - 5.28 = 0.03x

1.32 = 0.03x

x = 44

Answer 2

13% of x + 20% of 33 = (x+20)*16%

0.13x + 6.6 = 0.16(x+20)

13x + 660 = 16(x+20)

13x + 660 = 16x + 320

13x + 660 - 320 = 16x

660 -320 = 16x - 13x

340 = 3x

340/3 = x

x=113 and 1/3