An air conditioner can coo the hall in 25 minutes while another takes 30 minutes to cool under similar conditions. if both air conditioners are switched on at same instance then how long will it take to cool the room?
Choose one.
A) about 16 minutes B) about 24 minutes C) about 14 minutes D) about 34 minutes E) about 4 minutes
Take LCM of 25 and 30 = 150   25*6= 
<gadget id="calculator">25*6</gadget>
<output>150</output>
150/ 30*5=150.   So if both are switched on together , room cooled in 150/(6+5)=150/11=13.64 minutes   13.64 can be round to 14 minutes , so about 14 minutes   ANSWER: about 14 minutes
<result>C</result>
An air conditioner can coo the hall in 25 minutes while another takes 30 minutes to cool under similar conditions. if both air conditioners are switched on at same instance then how long will it take to cool the room?