Birthday paradox

How large must the group of people be so that the probability that two people have a birthday on the same day of the year is greater than 90%?

Correct answer:

n =  41

Step-by-step explanation:

p1=13650.0027  q2=1364365=13650.0027 q3=1(1q2) 363365=1(10.0027) 3633650.0082 q4=1(1q3) 362365=1(10.0082) 3623650.0164  q5=1(1q4) 3654365=1(10.0164) 36543650.0271 q6=1(1q5) 3655365=1(10.0271) 36553650.0405 q7=1(1q6) 3656365=1(10.0405) 36563650.0562 q8=1(1q7) 3657365=1(10.0562) 36573650.0743 q9=1(1q8) 3658365=1(10.0743) 36583650.0946 q10=1(1q9) 3659365=1(10.0946) 36593650.1169 q11=1(1q10) 36510365=1(10.1169) 365103650.1411 q12=1(1q11) 36511365=1(10.1411) 365113650.167 q13=1(1q12) 36512365=1(10.167) 365123650.1944 q14=1(1q13) 36513365=1(10.1944) 365133650.2231 q15=1(1q14) 36514365=1(10.2231) 365143650.2529 q16=1(1q15) 36515365=1(10.2529) 365153650.2836 q17=1(1q16) 36516365=1(10.2836) 365163650.315 q18=1(1q17) 36517365=1(10.315) 365173650.3469 q19=1(1q18) 36518365=1(10.3469) 365183650.3791 q20=1(1q19) 36519365=1(10.3791) 365193650.4114 q21=1(1q20) 36520365=1(10.4114) 365203650.4437 q22=1(1q21) 36521365=1(10.4437) 365213650.4757 q23=1(1q22) 36522365=1(10.4757) 365223650.5073 q24=1(1q23) 36523365=1(10.5073) 365233650.5383 q25=1(1q24) 36524365=1(10.5383) 365243650.5687 q26=1(1q25) 36525365=1(10.5687) 365253650.5982 q27=1(1q26) 36526365=1(10.5982) 365263650.6269 q28=1(1q27) 36527365=1(10.6269) 365273650.6545 q29=1(1q28) 36528365=1(10.6545) 365283650.681 q30=1(1q29) 36529365=1(10.681) 365293650.7063 q31=1(1q30) 36530365=1(10.7063) 365303650.7305 q32=1(1q31) 36531365=1(10.7305) 365313650.7533 q33=1(1q32) 36532365=1(10.7533) 365323650.775 q34=1(1q33) 36533365=1(10.775) 365333650.7953 q35=1(1q34) 36534365=1(10.7953) 365343650.8144 q36=1(1q35) 36535365=1(10.8144) 365353650.8322 q37=1(1q36) 36536365=1(10.8322) 365363650.8487 q38=1(1q37) 36537365=1(10.8487) 365373650.8641 q39=1(1q38) 36538365=1(10.8641) 365383650.8782 q40=1(1q39) 36539365=1(10.8782) 365393650.8912 q41=1(1q40) 36540365=1(10.8912) 365403650.9032 q42=1(1q41) 36541365=1(10.9032) 365413650.914 n=41

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