OG详解-OG5 数学1 Q25

Choice A is correct. It’s given that the result of increasing the quantity x by 400% is 60. This can be written as x+ 400100​​x = 60, which is equivalent to x+4x = 60, or 5x = 60. Dividing each side of this equation by 5 yields x = 12. Therefore, the value of x is 12.
Choice B is incorrect. The result of increasing the quantity 15 by 400% is 75, not 60. Choice C is incorrect. The result of increasing the quantity 240 by 400% is 1,200, not 60. Choice D is incorrect. The result of increasing the quantity 340 by 400% is 1,700, not 60.