We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website.
Please click on "Accept cookies" if you agree to the setting of cookies. Cookies that do not require consent remain unaffected by this, see
cookie policy and privacy policy.
DECLINE COOKIES

six years ago Albert was 1/5 as old as his mother. his mother is now 3 times as old as alert. how old is his mother?

Guest Nov 13, 2015

#1**+5 **

Let his mother's age 6 years ago = x and his age then was (1/5)x

And now we know that :

3 times his age now = his mother's age now....so........

3 [ (1/5)x + 6 ] = x + 6 simplify

(3/5)x + 18 = x + 6 subtract (3/5)x , 6 from both sides

12 = (2/5)x multiply both sides by 5/2

12 [ 5/2] = x = 60/2 = 30

This was his mother's age 6 years ago......so.....she must be 36, now

CPhill Nov 13, 2015

#1**+5 **

Best Answer

Let his mother's age 6 years ago = x and his age then was (1/5)x

And now we know that :

3 times his age now = his mother's age now....so........

3 [ (1/5)x + 6 ] = x + 6 simplify

(3/5)x + 18 = x + 6 subtract (3/5)x , 6 from both sides

12 = (2/5)x multiply both sides by 5/2

12 [ 5/2] = x = 60/2 = 30

This was his mother's age 6 years ago......so.....she must be 36, now

CPhill Nov 13, 2015

#2**+5 **

**six years ago Albert was 1/5 as old as his mother. his mother is now 3 times as old as alert. how old is his mother?**

**\(\begin{array}{|l|r|r|} \hline & Albert(a) & Mother(x) \\ \hline \text{Now} & a & \quad (1) \quad x = 3a \\ -6\text{ years} & \quad (2) \quad a-6 = \frac15(x-6) & x -6 \\ \hline \end{array}\\ \begin{array}{lrcl} (1)& x &=& 3a \\ & a &=& \frac{x}{3} \\ \\ \hline \\ (2)& a-6 &=& \frac15 (x-6) \quad & | \quad a = \frac{x}{3}\\\\ & \frac{x}{3}-6 &=& \frac15 (x-6)\\\\ & \frac{x}{3}-6 &=& \frac{x}{5} - \frac{6}{5} \quad & | \quad -\frac{x}{5}\\\\ & \frac{x}{3}- \frac{x}{5}-6 &=& -\frac{6}{5}\\\\ & \frac{x}{3}- \frac{x}{5}-6 &=& -\frac{6}{5} \quad & | \quad +6 \\\\ & \frac{x}{3}- \frac{x}{5} &=& 6-\frac{6}{5} \\\\ & \frac{5x-3x}{15} &=& \frac{30-6}{5} \\\\ & \frac{2x}{15} &=& \frac{24}{5} \\\\ & \frac{2x}{15} &=& \frac{24}{5} \quad & | \quad :2 \\\\ & \frac{x}{15} &=& \frac{12}{5} \quad & | \quad \cdot 15 \\\\ & x &=& \frac{12\cdot 15}{5} \\\\ & x &=& 12\cdot 3 \\\\ & x &=& 36 \\\\ \end{array}\\ \text{His mother is } \mathbf{36} \text{ years old.}\\\\ \begin{array}{lrcl} \\ \hline \\ (1)& a &=& \frac{x}{3} \quad & | \quad x = 36\\\\ & a &=& \frac{36}{3} \\\\ & a &=& 12 \\\\ \end{array}\\ \text{Albert is } \mathbf{12} \text{ years old.} \)**

heureka Nov 13, 2015