A) 24 because it a very simple
The intersection of the steps is just a fancy way of asking wi\hich numbers are in both equations so lets look and see :)
The 1st = 0...1...5...7...8
The 2nd =0........5...7........9
Answer = D {0, 5, 7}
Hope this helps have any questions let me know :)
Answer:
since the unknown amount can buy 100 pencils
he bought 70 pencils
therefore $4.50 can buy 30 pencils
so 1 pencils cost $4.50 /30=0.15