Name the element found in small amounts in the body that is needed to make hemoglobins for oxygen transport

About 70 percent of your body's iron is found in the red blood cells of your blood called hemoglobin and in muscle cells called myoglobin. Hemoglobin is essential for transferring oxygen in your blood from the lungs to the tissues.

      x/140 = 25/100

we need to find the x to find the x multiply 140 and 25

and what do you get 3500.   and what is 3500 divided by 100

= 35