Answer:
Elizabeth had 30 stamps originally.
Step-by-step explanation:
Let,
x be the number of stamps Elizabeth have.
Number of stamps given to John = 1/6 of x = [tex]\frac{1}{6}x[/tex]
Remaining stamps = [tex]x-\frac{1}{6}x = \frac{6x-1x}{6} = \frac{5}{6}x[/tex]
Stamps given to Peter = 1/5 of remainder = [tex]\frac{1}{5}*\frac{5}{6}x = \frac{1}{6}x[/tex]
Number of stamps left = 20
Now,
[tex]\frac{1}{6}x + \frac{1}{6}x + 20 = x\\\\\frac{1x+1x+120}{6} = x\\\\\frac{2x+120}{6} = x\\\\2x + 120 = 6x \\\\120 = 6x - 2x \\\\120 = 4x \\4x = 120[/tex]
Dividing both sides by 4
[tex]\frac{4x}{4}=\frac{120}{4}\\x=30[/tex]
Hence,
Elizabeth had 30 stamps originally.