15 bracelets because 21 minutes are taken to make a bracelet and she has 315 minutes to make bracelets so divide 315 by 21 and u get 15
The number of milligrams of aluminum is 400 times the number of milligrams of gold in the body.
<u><em>Explanation</em></u>
Lets assume, the number of milligrams of aluminum is
times the number of milligrams of gold in the body.
The body of a 154 pound person contains approximately 4 × 10⁻¹ milligrams of gold and 16 × 10¹ milligrams of aluminum.
So the equation will be...

So, the number of milligrams of aluminum is 400 times the number of milligrams of gold in the body.
Well 25% is the same as .25 or 1/4. So first you need to add X and Y so X+Y and since it is both you choose D