Though both are ratio problems on currencies, one I am getting right answer the way I am solving, where other is wrong. But, I didn't find what mistake I made! Can anyone clarify?
In a certain country, $8$ rubels worth $1$ schilling, and $5$ schilling are worth $1$ lemuw. In this country, $6$ lemuws are equivalent in value of what rubels?
$8$ rubel = $1$ Schilling
$40$ rubel = $5$ schilling = $1$ lemue
$240$ rubel = $6$ lemue
In nation Z, $10$ Terble coins equal $1$ Gallok. In nation Y, $6$ Barbar coins equal $1$ Murb. If Galok is worth $40\%$ more than a Murb, what is the ratio of the value of $1$ Terbel coin to the value of $1$ Barbar coin?
$140$ Galok = $100$ Murb $\rightarrow$ $7$ Galok = $5$ Murb
$1$ Murb= $6$ Barbar $\rightarrow$ $5$ Murb = $30$ Barbar
$1$ Gallok = $10$ Terbel $\rightarrow$ $7$ Gallok = $70$ Terbel
$7$ Galok= $5$ Murb= $30$ Barbar= $70$ Terbel
Terbel : Barbar = $70:30$ = $7:3$
Your mistake is in the second question. While the ratio of Gallok to Murb is 140:100, that does not mean 140 Galloks equal 100 Murbs.
The numbers should be reversed; 100 Galloks equal 140 Murbs. (Since a Gallok is worth more than a Murb, right?) Now continue your working as you did to get the correct answer.