Step 1: Radius of hemisphere $=$ radius of cone $= r = 7$ cm.
Step 2: Height of cone $$h = \text{Total height} - \text{radius of hemisphere} = 31 - 7 = 24\ \text{cm}$$
Step 3: Slant height of the cone :
$$l = \sqrt{r^2 + h^2} = \sqrt{7^2 + 24^2} = \sqrt{49 + 576} = \sqrt{625} = 25\ \text{cm}$$
Step 4: Total surface area $=$ CSA of cone $+$ CSA of hemisphere
$$= \pi r l + 2\pi r^2 = \pi r(l + 2r)$$
Step 5: $$= \frac{22}{7} \times 7 \times (25 + 14) = 22 \times 39 = 858$$
Hence the total surface area of the toy $= 858\ \text{cm}^2$.