James bought a total of 15 bottles of drinks for his team. each drink was either a bottle of water or a bottle of juice. he spent $1.50 on each bottle of water. he spent $3.00 on each bottle of juice. james spent a total of $28.50. how many bottles of juice did james buy?

James bought 4 bottles of juice.

Solution:

Given that  

Total Number of bottles bought by James = 15  

There are two types of bottles that are bottle of juice and bottle of water.  

Cost of one bottle of water =

Cost of one bottle of Juice =

Total amount spent on buying bottles =

Need to calculate number of bottles of juice bought by James.

Let’s assume number of bottles of juice bought by James be represented by variable x.

So Remaining bottles of out of 15 bottles will be bottle of water

So number of bottles of water =

Total amount spent on buying bottles = Price of x bottles of juice + Price of (15 – x) bottles of water

Solving above expression to get value of x.  

As number of bottles of juice bought by James be represented by variable x, hence the number of bottles of juice bought by James is 4.

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

2nd one in the first row is correct