Answer:
She has n= 4 side dishes.
Total side dishes ordered = 5n = 20
Explanation:
The total cost is given by
TC= 10 . 50 + 1 . 50 ( n − 1 )
She orders same 5 lunches for $ 75
$ 75= 5{ 10 . 50 + 1 . 50 ( n − 1 ) }
Or
Cost of 1 lunch would be $ 15
$ 75/5 = { 10 . 50 + 1 . 50 ( n − 1 ) }
or
$ 15 = 10 . 50 + 1 . 50 ( n − 1 )
$ 15-$ 10 . 50 = 1 . 50 ( n − 1 )
$ 4.5/ 1.5= n-1
$ 3= n-1
3+1= n
n= 4
She has n= 4 side dishes.
Total side dishes ordered = 5n = 20
She spent
$ 1.50 ( 4-1) = $ 4.5 each day or $22.5 on side dishes for 5 days.