Mrs.Santiago is 36 yrs. old and her son is 4 years old. When will the mother be thrice as old as her son?

36+x = 3(4+x)

To find out when the mother will be thrice as old as her son, we can set up an equation. Let's assume x represents the number of years from now.

In x years, Mrs. Santiago's age will be 36 + x, and her son's age will be 4 + x.

According to the question, the mother's age in x years will be three times her son's age in x years. Thus, we can write the equation as:

36 + x = 3(4 + x)

First, let's distribute the 3 on the right side of the equation:

36 + x = 12 + 3x

Next, we can solve for x by isolating the variable on one side:

2x = 36 - 12
2x = 24

Dividing both sides by 2 gives us:

x = 12

Therefore, in 12 years, Mrs. Santiago will be thrice as old as her son.