Solve the following problem using a matrix equation and inve
Solve the following problem using a matrix equation, and inverse matrix.
If there are 60 dimes and nickels worth $4.30 altogether, how many of each are there? What about 50 coins worth $4.00? 63 coins worth $5.25?
Solution
let number of dimes be x and number of nickels be y
then, x+y=60
one dime=10 cents and one nickel=5 cents
10x+5y=480
putting above two equations in matrices, [1 1] [x] =[60]
[10 5] [y] [480]
this becomes AX=B
X=A^-1B
Taking inverse matrix, X=1/-5 [5 -1] [60]
[-10 1] [480]
X=1/-5[300-480]
[-600+480]
X=[36]
[24]
x= 36 y =24
number of dimes=36
number of nickels=24
