There are two rows of numbers in the grid below. The upper row is complete, and in the lower row one number is missing. Find the number that keeps the same pattern as the upper row.
Show Hint
Look at how the first and third numbers combine to give the middle number.
Step 1: Read the pattern from the complete row. The upper row has 17, 102, 12. Try connecting the first and third numbers to get the middle one: half of 12 is 6, and 17 times 6 gives 102, which matches the middle number exactly.
Step 2: State the rule. The middle number equals the first number multiplied by half of the third number.
Step 3: Apply the rule to the lower row. The lower row has 15, ?, 10. Half of 10 is 5, and 15 multiplied by 5 gives 75.
Step 4: Check the answer against the options. 211, 125 and 117 do not come from this multiplication, so only 75 fits the pattern found in the upper row.
Final Answer: The missing number follows the same first times half of third rule as the upper row. \[ \boxed{75} \]
