Answer:
24
Step-by-step explanation:
18/n = 21/28 You can cancel, but calculators make that unnecessary. Cross multiply
21n = 18 * 28
21n = 504 Divide by 21
n = 504 / 21
n = 24
==================
12/16 = n / 64 Cross Multiply
16n = 12 * 64
16n = 768 Divide by 16
n = 768/16
n = 48
