OG详解-OG10 数学2 Q1

Choice D is correct. Since 1 yard is equal to 3 feet, 64 yards is equal to 64 yards(3 feet1 yard​​ ) or 192 feet. It follows that 64 yards per second is equivalent to 192 feet per second. Therefore, the object’s speed is 192 feet per second.
Choice A is incorrect. A speed of 61 feet per second is equivalent to 61​3​, not 64, yards per second. Choice B is incorrect. A speed of 67 feet per second is equivalent to67​3​, not 64, yards per second. Choice C is incorrect. A speed of 94 feet per second is equivalent to  94​3​ , not 64, yards per second.