Each day, Robert eats 40% of the pistachios left in his jar at that time. At the end of the second
day, 27 pistachios remain. How many pistachios
were in the jar at the start of the first day?

At the beginning of the first day there were 75 pistachios in the jar.

Step-by-step explanation:

Given that each day, Robert eats 40% of the pistachios left in his jar at that time, and at the end of the second day, 27 pistachios remain, to determine how many pistachios were in the jar at the start of the first day you must perform the following calculations:

100 - 40 = 60

60 = 27

100 = X

100 x 27/60 = X

2700/60 = X

45 = X

60 = 45

100 = X

100 x 45/60 = X

4500/60 = X

75 = X

Therefore, at the beginning of the first day there were 75 pistachios in the jar.

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

its totaly b

your welcome btw