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?
Choices
A) 138  B) 198  C) 267  D) 297  E) 191
The clock takes 12 secs to strike 9.00. So there are 8 gaps between 9 strikings. So the gap between the striking is 12/8= 
<gadget id="calculator">12/8</gadget>
<output>3/2 = around 1.5</output>
1.5 seconds.   To strike 2.00 it takes= 1.5 seconds.   To strike 3.00 it takes = 3 seconds.   To strike 4.00 it takes = 4.5 seconds   ................   ................   To strike 12.00 it takes = 16.5 seconds.   So it takes a total of 1.5 + 3 + 4.5 + . . . . . . + 16.5 = 1.5 ( 1 + 2 + 3 + .... + 11) = 99 seconds to strike 12 hours.   For 24 hours it takes 99 × 2 = 198 seconds.   Answer:198
<result>B</result>
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?