Answer :
[tex] \frac{16}{18~+~x} ~=~ \frac{1}{1.5} [/tex]
18 + x = 1.5 (16)
18 + x = 24
x = 6
24 Tail
&
40 total coins
18 + x = 1.5 (16)
18 + x = 24
x = 6
24 Tail
&
40 total coins