First, convert everything to feet.
24 inches become 2 feet, and 30 inches become 2.5 feet.
Then, calculate the square feet of counter top. To do that, multiply length by height.
2 x 6 = 12
2.5 x 4 = 10
Then add them together
10 + 12 = 22
And then calculate per square feet, so multiply 22 by the cost, 42.
22 x 42 = 924
The cost would be $924