Stamps 79154

Milan has four times more marks than Anka. Anka has twice as few grades as Juro. They have a total of 91 stamps. How many stamps does each person have?

Correct answer:

A =  13
M =  52
J =  26

Step-by-step explanation:

$$\begin{gathered} M=4\cdot A \\ A=J/2 \\ A+M+J=91 \\ 4A-M=0 \\ 2A-J=0 \\ A+J+M=91 \\ Row2-\frac{2}{4}\cdot Row1\to Row2 \\ 4A-M=0 \\ -J+0.5M=0 \\ A+J+M=91 \\ Row3-\frac{1}{4}\cdot Row1\to Row3 \\ 4A-M=0 \\ -J+0.5M=0 \\ J+1.25M=91 \\ Row3+Row2\to Row3 \\ 4A-M=0 \\ -J+0.5M=0 \\ 1.75M=91 \\ M=\frac{91}{1.75}=52 \\ J=\frac{0-0.5M}{-1}=\frac{0-0.5\cdot 52}{-1}=26 \\ A=\frac{0+M}{4}=\frac{0+52}{4}=13 \\ A=13 \\ J=26 \\ M=52 \end{gathered}$$

Try another example