Question

3:___::15:21 Please tell step by step​

Answer 1

Answer:

4.2

Step-by-step explanation:

3:__::15:21

3:x::15:21

By multiplying 3×21=63

x×15= 15x

Therefore, 15x=63

x=63/15

x= 4.2

OR

3/x=15/21

By cross multiplication, 15x=3×21

x=4.2

Answer 2

Answer:

$3 : x \: \: : : \: 15 \: : 21 \\ here \: x = 21 \div 5$