Concept: Suppose A is a square matrix of 2 rows and 2 columns A=[
a
b
c
d
] The determinant is; |A|=[ad−bc] Calculation: A=|
p
q
r
s
| p,q,r and s are any four different prime numbers less than 20 . Here we have to find the maximum value of the determinant so we have to take maximum value for p and All prime numbers less than 20=2,3,5,7,11,13,17,19 So, p=17,q=2,r=3 and s=19 A=|