Everyday, navya's teacher randomly picks a number from 1 to 20 to be the number of the day. the number of the day can be repeated. there are 180 days in the school year. predict how many days the number of the day will be greater than 15

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b