Let the two numbers be x (larger) and y (smaller)
Given:
1) x - y = 56
2) x + y = 208
Add the two equations
(x - y) + (x + y) = 56 + 208
2x = 264
x = 132
Find the smaller number
x + y = 208
132 + y = 208
y = 76
Answer: The smaller number is 76

Find cost per orange
Cost: 5 oranges for 2 cents
1 orange costs = 2 ÷ 5 = 0.4 cents
Find selling price per orange
Sell: 4 oranges for 3 cents
1 orange sells for = 3 ÷ 4 = 0.75 cents
Find profit per orange
Profit per orange = 0.75 - 0.4 = 0.35 cents
Find number of oranges to make 420 cents profit
Number of oranges = 420 ÷ 0.35 = 1200
Answer: Costas must buy and sell 1,200 oranges to make a profit of 420 cents