Use mental math to find the value of 15/124·230/30:230/124

Okay, the first thing to do is to make it so you're multiplying everything instead of dividing by that last fraction. To divide by a fraction, you just multiply by its reciprocal. So then, it's 15/124 x 230/30 x 124/230. After that, let's organize it into one single giant fraction since order of operations allows us to arrange division and multiplication however we want. Then it's 15x230x124 / 124x30x230. Then, you'll notice that the 230s and 124s can both be canceled out, leaving 15/30. After simplifying, your final answer is 1/2.