Question

B’s age 8 years ago is 60% more
than A’s age 8 years ago. If ratio
between Present ago of A and B
is 3 : 4, then find B’s age four
years hence

Answer 1

Answer:

Solution: By eliminating the row and column of an element, the determinant of remaining elements is the minor of the element, i.e. M i × j {{M}_{i\times j}} Mi×j and by using formula ( − 1 ) i + j M i × j {{\left( -1 \right)}^{i+j}}{{M}_{i\times j}} (−1)i+jMi×j we will get the cofactor of the element.