can someone please help me out marking brainliest for a good explanation (picture)

Step-by-step explanation:
9 a = soln
3:9 = 6:n
or, 3/9 = 6/n
or, 3n = 54
or, n = 54/3
so, n = 18
b = soln
n/10 = 6/15
or, 15n = 60
or, n = 60/15
so, n= 4
10) a = 15% of 450
= 15/100 * 450
= 15/10 * 45
or, 15/2 * 9
or, 135/2
= 67.5 g
b= 125% of 60
= 125/100 * 60
= 5/4 * 60
= 5*15
= $75