Christopher is taking a multiple choice test with a total of 100 points available. Each question is worth exactly 2 points. What would be Christopher's test score (out of 100) if he got 10 questions wrong? What would be his score if he got xx questions wrong?

If im not wrong, if every question is 2 points of 100 points in total means that are 50 questions, so if he gets 10 wrong then he would be losing 20 points which his final grade would be 80!

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