Answer:
Calenders= 400
Date book= 100
Step-by-step explanation:
In this instance we will derive an equation to solve the problem.
Assume that quantity of calenders is q.
Therefore
500-q = number of date books
Total price = summation of (price *quantity)
$350= 0.75q+ 0.5(500-q)
350= 0.75q+ 250- 0.5q
350= 0.25q+ 250
0.25q= 350-250= 100
q= 100/0.25= 400
So calenders is equal to 400
And date books= 500-q= 500-400
Date books = 100