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Popular Word Problems >

Three years from now, David's age will be three times his age 12 years ago. How old was David 12 years ago?

Solution

T h ree ye a rs f ro m n o w, D a v i d^{'} s a g e w i ll b e t h ree t im es hi s a g e 12 ye a rs a g o . Ho w o l d w a s D a v i d 12 ye a rs a g o ?

Solution

Davi d^{'} s age 12 years ago : 7 \frac{1}{2}

Solution steps

Translate the problem into an equation:

x + 3 = 3 (x - 12)

Solve for

x, x + 3 = 3 (x - 12) : x = \frac{39}{2}

Find David's age 12 years ago:

7 \frac{1}{2}

Davi d^{'} s age 12 years ago : 7 \frac{1}{2}

Popular Examples

two more than the quotient of a number and 3 is equal to 5 The product of a number and negative three is twenty-seven The difference between a number and −25 is equal to the number times 18 three more than twice a number is no more than eleven six more then twice a number is at most thirty six