What is the value of D, if A : C = B : D in the given table? 

A	B	C	D
25	40	30	?

Correct option is B

Given: A : C = B : D, where A = 25, B = 40, C = 30, D = ?
Formula Used:
For proportional values,
​$$\frac{A}{C} = \frac{B}{D}, \quad \text{hence} \quad D = \frac{B \times C}{A}$$​​
Solution:
​$$\text{Given: } A : C = B : D \\\frac{A}{C} = \frac{B}{D}, \\\frac{25}{30} = \frac{40}{D}, \\\ \\D = \frac{40 \times 30}{25} = \frac{1200}{25} = 48. \\\ \\\text{Thus, the value of } D \text{ is } 48.$$​​