NDA2021MathematicsDeterminantsActual
Let A= | array lr p & q r & s array | where p, q, r and s are any four different prime numbers less than 20 . What is the maximum value of the determinant?
Options
- A215
- B311
- C317
- D323
Correct answer
C. 317
Step-by-step solution
A= | array ll p & q r & s array | , where (p, q, r, s) prime number 20 (p, q, r, s)=(2,3,5,7,11,13,17 and 19) Now, A=p s-q r . For A_ max , product (p . s) should be max. and product (q.r) should be min. A_ . =p s-q r=19 17-2 3=317