While riding her bike to the ocean and back home 6 times, Marissa timed herself at 50min, 51min, 64min, 50min, 65min, and 69min. She had set a goal of averaging 57 minutes for her rides. How many minutes will she need to spend on her seventh ride to attain her goal?

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

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11 -1> 1 -1+ a

-12 > a

b. b < 1 might be the correct answer