The thyroid of a teaching model gives, for an iodine supply of s (as a share of the normal supply)…

The thyroid of a teaching model gives, for an iodine supply of $s$ (as a share of the normal supply), a thyroid hormone level $h = \dfrac{-1 + \sqrt{1 + 8s}}{2}$ and a TSH level $\dfrac{2}{1 + h}$. Both levels are shares of the normal level, and $s = 1$ gives $h = 1$ and TSH $= 1$.

1. Find the hormone level, as a per cent of normal, for an iodine supply of $50\%$.

1. Find the TSH level, as a per cent of normal, for the same supply.

1. Find the hormone level for an iodine supply of $25\%$.