Answer:
Mr Kaplan bought 9 child tickets and 2 adult tickets.
Step-by-step explanation:
- Mr Kaplan bought 11 tickets
- He spent $50
- Child tickets cost $4 each
- Adult tickets cost $4 each.
We want to know how many adult ticket and child ticket Mr Kaplan bought.
Better still, we want to know exactly how many $4's and $7's make $50.
Let us try out the numbers that sum up to 11.
10 + 1 = 11
9 + 2 = 11
8 + 3 = 11
7 + 4 = 11
6 + 5 = 11
Next, let us check which one(s) of these number when applied to the costs of tickets gives 50
(10×$4) + (1 × $7) = $47 ≠ $50
(10×$7) + (1×$4) = $74 ≠ 50 (10×$7, 9×$7, 8×$7, and 7×$7 are already too much, it is reasonable to ignore them)
Let's try the next one
(9×$4) + (2×$7) = $50 (This works)
Next,
(8×$4) + (3×$7) = $53 ≠ 50
(7×$4) + (4×$7) = $56 ≠ 50
(6×$5) + (5×$7) = $65 ≠ 50
So, we can conclude that Mr Kaplan bought 9 child tickets and 2 adult tickets.
