The correct answer is: $81\text{ kg}=12\text{ st }10.6\text{ lb}\ (\approx178.57\text{ lb})$
Explanation
Convert kilograms to pounds, then convert pounds to stones (1 stone = 14 lb).
Steps:
- Convert to pounds:
$$178.5744323658\text{ lb}=81\times2.2046226218\text{ lb}$$
- Find whole stones:
$$\text{stones}=\left\lfloor\frac{178.5744323658}{14}\right\rfloor=12$$
- Pounds remaining:
$$\text{pounds remaining}=178.5744323658-12\times14=10.5744323658\text{ lb}\approx10.6\text{ lb}$$
Therefore, 81 kg ≈ 12 st 10.6 lb (which is about 178.57 lb).
(If you prefer ounces: 10.5744 lb ≈ 10 lb 9.2 oz, so 12 st 10 lb 9.2 oz.)