The ratio of adults to kids attending a play is 8:5 based on this ratio if 390 people attend how many are kids

Answer 1

5/13 = x/390

Cross multiply and solve for x.

Answer 2

390 was the total, so
number of adults --- 8x
number of kids ----- 5x

8x+5x = 390
13x = 390
x = 30

so 240 adults and 150 kids

check:
240+150 = 390
240 : 150 = 24:15 = 8 : 5