Question

Rico thinks of a number between 30 and 40 that is represented by

Answer 1

Hello,

x,y,z∈ IN

$x=\frac{3}{4}*y$
$y=\frac{1}{3}*z$

$140$
$46\leq\ y\ \leq\ 50 ==>\ \frac{46*3}{4}\leq\frac{3y}{4}\leq\frac{50*3}{4}$
$35\ \leq\ z\ \leq\ 37$==>
 x∈{35,36,37}
 y∈{47,48,49}
 z∈{141,144,147}

We must go futher:

if x=35 then y=4*35/3=46.666 not good , not whole
if x=36 then y=4*36/3=48 ok
if x=37 then y=37*4/3=49.333.. not good

So there is only one solution (36,48,144) for (x,y,z)

No problem with z for z=3/1*4/3*x=4x ==>whole.