Answer:
He can save 20 dollars
Step-by-step explanation:
He can buy one 100 token amount and one 25 token amount. This will cost 20 + 10 dollars, or 30 dollars. If each friend buys 25 tokens, it will cost
10 * 5 dollars, or 50 dollars. 50 - 30 = 20. So he can save 20 dollars.