For this question, we can use relations for pH and pOH. We calculate as follows:
pOH = -log [OH-]
pOH = -log [1.83x10^-7 M]
pOH = 6.74
pH + pOH = 14
pH = 14 - 6.74
pH = 7.26
pH = -log [H3O+]
7.26 = -log[H3O+]
[H3O+] = 5.46 x 10^-8 M
Hope this answers the question. Have a nice day.
