Question

Fido weighs $26$ pounds more than Fifi.

Fifi weighs $12$ pounds less than Rover.

If sum of their weights is $71$, how much does Fifi weighs $?$

Answer 1

Find weight of Fifi:

Let Fifi weighs $x$ pounds.

Then, weight of Fido will be $(x+26)$ pounds

Fifi weighs $12$ pounds less than Rover.

Therefore, the weight of Rover will be $12$ pounds more than Fifi.

So the weight of Rover will be $(x+12)$ pounds.

Sum of weight of Fifi, Fido and Rover will be as follows:

$$\begin{gathered} =x+(x+26)+x+12 \\ =3x+38 \end{gathered}$$.

Sum of their weights is $(3x+38)$ pounds,

According to the problem, the sum of their weights is equal to $71$ pounds:

$3x+38=71$

$\Rightarrow$ $3x=33$

$\therefore$ $x=11$

Hence, Fifi weighs $\mathbf{11}\mathbf{}\mathbf{\text{pounds}}$.