Answer:
Explanation:
Let B be the number of black cars and S the number of silver.
We know that B/S = 7/4
We also know that B - S = 12
Rearrange the first: B = 7S/4
B - S = 12
7S/4 - S = 12
7S - 4S = 48
3S = 48
S = 16
B/S = 7/4
B/16 = 7/4
4B = 112
B = 28
B + S = 44 cars
I can't add the tape diagram here, but show two ribbons (tapes) for each car color and drawn so one can see the relative numbers of each.