Step 1: Name the four quantities.
Let Sachin's runs and balls be $S_r, S_b$, and Lara's runs and balls be $L_r, L_b$.
Step 2: Translate each sentence.
Sachin's runs are 10 more than Lara's balls: $S_r = L_b + 10$. Sachin's balls are 5 less than Lara's runs: $S_b = L_r - 5$. Together they scored 105: $S_r + L_r = 105$. Sachin faced 10 balls fewer than Lara: $S_b = L_b - 10$.
Step 3: Link Lara's runs and balls.
From $S_b = L_r - 5$ and $S_b = L_b - 10$, set them equal: $L_r - 5 = L_b - 10$, so $L_b = L_r + 5$.
Step 4: Express Sachin's runs in terms of Lara's runs.
Substitute into $S_r = L_b + 10$: $S_r = (L_r + 5) + 10 = L_r + 15$.
Step 5: Use the total runs.
Put this into $S_r + L_r = 105$: $(L_r + 15) + L_r = 105$, so $2L_r = 90$ and $L_r = 45$.
Step 6: Compute Sachin's runs.
Then $S_r = 45 + 15 = 60$.
\[ \boxed{60} \]