<PRE><B>Question 952735</B>
12 hrs/day for 12 days is {{{ 12*12 = 144 }}} hrs
4 hrs/day for 4 days is {{{ 4*4 = 16 }}} hrs
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{{{ 12 + 4 = 16 }}} m of tunnel
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12 persons dig 
12 m of tunnel in
144 hrs
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4 persons dig
4 m of tunnel in
144 hrs
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16 persons dig
16 m of tunnel in
144 hrs
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{{{ 9*16 = 144 }}} persons dig
16 m of tunnel in
16 hrs
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144 men are required 
To explain:
{{{ 16 = (1/9)*144 }}}, so to dig
the same number of tunnels in
1/9 the time, it will take
9 times as many men
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