a clock strikes every hour once at 1.00 twice at 2.00 and so on. the clock takes 6 seconds to strike 5.00 and 12 seconds to strike 9.00 the time needed to strike 1.00 is negligible. how long does the clock need for all its striking in 24 hours?

• the clock takes 12 secs to strike 9.00.
  so 9----12
  2---?
  2/9 *12=6..
  lokewise
  we can get all striking times at 2.00,3.00,4.00...12.00
  then the striking secs are 0+2+4+5+6+8+9+10+12+13+14+16=99.
  but these are only for 12hrs.
  In the qn they asked for 24hrs so ans becomes== 2(99)=198secs
• 12 years agoHelpfull: Yes(2) No(4)
• It means to cover 4 intervals it takes 6 sec
  for 1 intervals=6/4=3/2
  for 24 hours there is 23 interval=23*3/2
  69/2=34.5 seconds to strike
  but form 9.00 to 1.00 time neede is negligible so=total time=34.5-(3*3/2*2)=23.5 sec
• 12 years agoHelpfull: Yes(0) No(13)
• strike pattern: 1+2+3+4+5+6...+12+1+2+3....12
  So, total strikes in 24 hrs =2*[(122)*(2*1+ (12-1)*1)]=156
  Now,the clock takes 6 seconds to strike 4 times.{see 2nd line of question.)
  hence to strike 156 times, time taken=(64)*156=6*39= 234 sec
  
• 12 years agoHelpfull: Yes(0) No(4)
• The clock takes 6 seconds to strike 5.00 and 12 seconds to strike 9.00
  
  Between 5 and 9 that is 4 hrs there is a difference +1.5 second
  
  At 5 O clock ……time taken 6 sec
  At 6………6+1.5=7.5 sec
  At 7………7.5+1.5=9 sec
  At 8………9+1.5=10.5 sec
  At 9………10.5+1.5=12 sec
  
  Rest you workout friend and don’t expect me to do your home work
  Any way have you answered right
• 10 years agoHelpfull: Yes(0) No(2)