A shop sells laptops at $600 each and a smartphone at $400. Celine buys two laptops and four smartphones for her children. How much change does she get back if she has $3000? Let's answer step by step:
The cost of the two laptops is 2 x $600 = $1200. The cost of the four smartphones is 4 x $400 = $1600. Thus, the total cost of all the items is $1200 + $1600 = $2800. Therefore, Celine gets a change of $3000 - $2800 = $200. The answer: 200.