Grouped Distribution 1
In the case of a large number of measures it is usual to group
the marks of 40 students in a test are shown below
58 91 63 72 67 11 6 81 57 53 16 44 75 52 57 65 44 39 26 51 37 43 69 56 35 76 85 29 65 47 25 32 66 49 42 62 51 71 37 58​

the answer is d. 75%

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