2 men dug a swimming pool in 30 days. If they used 15 men to dig another similar pool, how long will it take?  Select the correct option.
A) 5
B) 10
C) 6
D) 4
E) 2
M1*41=M2*42   2*30=15*42 =&gt; 42=4   Answer:4
<result>D</result>
2 men dug a swimming pool in 30 days. If they used 15 men to dig another similar pool, how long will it take?