hii all..herz an intrestin question... Q How many digits are used to make a book containing 500 pages? wot cud b da ansr..??? um gettn 1791 as ansr..
1 digit – 10 2 digit – 2 x 90 = 180 3 digit – 3 x 401 = 1203 Total 1393
1. from page no. 1-9 : 1x10=10 from page no. 10-99 : 2x90=180 from page no. 100-500 : 3x401=1203 10+180+1203= 1393 2. 0 1 2 3 4 5 6 7 8 9 10 digits are used. what u say.....
somebody tell me where did 91-99 go !
how i find dat....lemme xplain... each number frm 1 to 9 comes 20 times from 1 to 99...from here we can calculate no of digits i.e 20*9=180 digits n frm 1 to 99, "9" zeroes are there..i.e in 10,20,30...90 now lets cum to 3 digits....strting from 100 to 199...we vil add zeroes of 100 at later stage...!!!1 so 1 wil cum at 100's place at 100 times and 1 wil cum at 10s place...10 times and 1 wil cum at unit's place=10 times so no of ones=180 now total no of ones=100+10+10=120 now lets calculate other digits... no of twos vil cum=20 times(10+10, same funda as we hv calculated in finding no of ones except there is no 100's place) so...rest of the digits except 1 wil cum 20 times.. so total no of digits included 2 =9*20=180 so total no of digits from 100 to 199=120+180=400 i.e 400+2(no of zeroes in 100)=402 this funda vil go on..n vil calculate no of digits from 200-300 which is again 402 nd 300-400 again 402 nd 400-500 again 402 so 402*4=1608 nd final ansr is 1608+180=1788 no of digits.. correct mee if um wrong.. thnx..
i think the answer is 1392
Pages 1-9 : 9 Pages 10-99 : 2*90 = 180 Pages 100-500 : 3*401 = 1203 Therefore, total no. of digits used = 9+180+1203 = 1392.
hii.. wots wrong in ma aaproachh.....?????
your written solution is very complex. but if u elobrate it i can tell u wats wrong.