Answer:
B. 30
Explanation:
The mosaic tile has a trapezoidal shape, so that its area can be determined as follows;
Area of a trapezium =
(a + b)h
where: a and b represent the length of its plane sides, and h is the height.
Area of a mosaic tile =
(4 + 6) 4
= 10 x 2
Area of a mosaic tile = 20 square inches.
But, Dan wants to cover a 600 square inch area.
So that the number of tiles needed =

= 30
The number of mosaic tiles needed by Dan is 30.