Answer:
35:15
Step-by-step explanation:
7:3=10 (7+3)
14:6=20 (14+6)
21:9=30 (21+9)
28:12=40 (28+12)
35:15=50 (35+15)
There is a more mathematical way to solve this but it isn't coming to mind rn so
Answer: 9/2π
20 / 9 = 10π s
20 /9 *10π= s
2 /9 π = s