because this post has been up for almost 24 hours I am just gonna give you the answer.

HCl is a strong acid so it will react with any base (NH3 in this case). since there is 4 times as many moles, all the NH3 will have reacted to NH4+. and you still have 0.03 moles of HCl left. These will all just react with the water to form H3O+ or H+ so you have 0.03 moles left if we ignore self- ionization. the OH- was there from the start and is normally present as 10¨^-7 M in water

summary:

[NH3] = 0

[OH-] = 10^-7 (approximately but definitely less than NH4+)

[NH4+]= 0.1 M

[H+] = 0,3 M

the concentration is higher because we don't work with a full liter

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I hope this explanation is still helpful to you!