To simplify, we need to find a number that can divide both the numerator and denominator equally. Can you find a number that will do this? I can't. So it is already simplified.
1.87 is 8.5% of 22 so 8.5% of 80 is 0.085 x 80 so $6.80
This is complicated because I’m typing on a phone, but
24:30 simplified is 4:5
30:54 simplified is 5:9
10:5 simplified is 2:1
5:15 simplified is 1:3
32:72 simplified is 4:9
72:104 simplified is 9:13
56:7 simplified is 8:1
7:63 simplified is 1:9
