Question

of the following transition metals, the maximum number of
oxidation states are exhibited by
A
Cobalt (Z = 27)
B
Iron (Z = 26)
С
Titanium (Z = 22)
D
Manganese (Z = 25)​

Answer 1

Here b is common on both sides so lets make it equal as their lcm is 36 we can make b 36.

so a:b = 5:9

=>a:b = 5*4:9*4 = 20:36

now b:c = 4:7

=>b:c = 4*9:7*9 = 36:63

Now we can equate both

a:b:c = 20:36:63