Lara has three cats: socks, princess, and luna. the ratio of sock's weight to princess's weight is 4: 5. the ratio of princess's weight to luna's weight is 6: 7. what is the ratio of sock's weight to luna's weight?

A = Sock's weight
b = Princess' weight
c = Luna's weight

a : b = 4 : 5
b : c = 6 : 7

at this point, we have to change the 2 ratios (a : b and b : c) into one ratio (a : b : c)
to do that, we have to change the ratio number so the number b in both ratio is the same

a : b = 4 : 5 = 24 : 30
b : c = 6 : 7 = 30 : 35
From that we can conclude that
a : b : c = 24 : 30 : 35

Since we're looking for the ratio of Sock's weight to Luna's weight, it will be
a : c = 24 : 35