Answer:
The carton of eggs at Supermarket B is

Explanation:
The price of a carton of eggs at SuperMarket A is $2.10
The price of a carton of eggs at Supermarket B is 40% less than the price of Supermarket A
Just to make it easier, I'm going to call Supermarket A Safeway and Supermarket B Walmart.
The price of a carton of eggs at Safeway is 100% of the price, which is $2.10
The same carton of eggs cost 40% less than 100% of $2.10 at Walmart, so 60% of $2.10
60% of something can be represented by multiplying that number by 0.6
- 60% of $2.10
- 0.6 * $2.10
- $1.26
The carton of eggs at Walmart(Supermarket B) costs $1.26
-Chetan K