If 5 men can build a house in 12 days, how many men are required to build the same house in 15 days?

Here are the solutions to the problems:

Question 9: If 5 men can build a house in 12 days, how many men are required to build the same house in 15 days?

Step 1: Identify the relationship between men and days.
The number of men and the number of days to build a house are inversely proportional. This means that the product of men and days remains constant ($M_1 D_1 = M_2 D_2$).

Step 2: Substitute the given values.
$M_1 = 5$ men, $D_1 = 12$ days.
$D_2 = 15$ days. Let $M_2$ be the unknown number of men.

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