It's just that people today don't care enough about maths

Math lessons in 1980:
A merchant buys diamonds for 100$ each and sells them for 120$ each
If he buys 10 diamonds, what is the maximum profit he can make?
Math lessons in 1990:
A merchant buys diamonds for 100$ each and sells them for 120$ each, which means he makes 20$ profit for each diamond he sells.
If he buys 10 diamonds, what is the maximum profit he can make?
Math lessons in 2000:
A merchant buys diamonds for 100$ each and sells them for 120$ each, which means he makes 20$ profit for each diamond he sells.
Explain why he can make 200$ profit if he buys 10 diamonds.
Math lessons in 2010:
A merchant buys diamonds for 100$ each and sells them for 120$, which means he makes 20$ for each diamond he sells.
If he buys 10 diamonds, he can make a maximum profit of 200$. Underline: '200$'
Math lessons in 2020:
A merchant buys diamonds for 100$ each and sells them for 120$, which means he makes 20$ for each diamond he sells.
Do you think the merchant should be satisfied with his job? There are no wrong answers
Education in maths is going waaaaaaay downhill...