Answer:
William has a total of 66 chairs.
Step-by-step explanation:
Let the number of chairs in each row be 'x'.
Also let the Total number of chairs be 'y'.
Given:
If he arranges the chairs in seven rows of the same length he has three chairs left
Number of rows = 7
Number of chairs left = 3
Now we can say that;
Total number of chairs will be equal to number of chairs in each row multiplied by Number of rows plus Number of chairs left.
framing in equation form we get;
Also Given:
If he arranges the chairs in five rows of the same length he has 21 chairs left
Number of rows = 5
Number of chairs left = 21
Now we can say that;
Total number of chairs will be equal to number of chairs in each row multiplied by Number of rows plus Number of chairs left.
framing in equation form we get;
Now we know that Total number of chairs are same.
Hence we can say that both the equations are equal.
Combining like terms we get;
Dividing both side by 2 we get;
So we can that there are 9 chairs in each row.
Now to find the total number of chairs he has we will substitute value of x in any of the equation we get;
Hence William has a total of 66 chairs.