Answer:
$2520
Explanation:
Taking the dimensions of the office floor from the plan to be;

Area of the floor to be covered will be the product of the sides dimensions

Cost of putting tile on the floor
1ft²=$1
420ft²=?
=

=$420
Cost of putting a carpet on the floor
1ft²=$5
420ft²=?

=$2100
Estimated cost
Total estimated cost =cost for putting tiles+cost for putting carpet
=$420+$2100=$2520