```ts
export function hourRate(rate: number): number {
  return rate;
}

/** Pay for a week, with overtime beyond forty hours. */
export function weekPay(hours: number, rate: number): number {
  if (hours > 40) {
    const excessHours = hours - 40;
    return Math.floor((excessHours * hourRate(rate) * 1.5) + hourRate(rate) * 40);
  }
  return hours * hourRate(rate);
}
```