He got 200*.9=<<200*.9=180>>180 RSVP

Of those only 180*.8=<<180*.8=144>>144 people showed up

So only 144-10=<<144-10=134>>134 got him gifts and hence need thank you cards.

# Answer

134
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Jack wants to send thank you cards to everyone who got him a gift for his wedding.  He sent out 200 invitations.  90% of people RSVPed but only 80% of people who RSVPed actually showed up.  Then 10 people who showed up didn't get a gift.  How many thank you cards does he need?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
134
Jack wants to send thank you cards to everyone who got him a gift for his wedding.  He sent out 200 invitations.  90% of people RSVPed but only 80% of people who RSVPed actually showed up.  Then 10 people who showed up didn't get a gift.  How many thank you cards does he need?
train