An air conditioner can coo the hall in 10 minutes while another takes 15 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 the correct choice from the following answers
A) 5 minutes	B) 6 minutes	C) 3 minutes	D) 8 minutes	E) 10 minutes
Take LCM of 10 and 15 = 30   10*3= 
<gadget id="calculator">10*3</gadget>
<output>30</output>
30/ 15*2=30.   So if both are switched on together , room cooled in 30/(3+2)=30/5= 
<gadget id="calculator">30/5</gadget>
<output>6</output>
6 minutes   ANSWER: 6 minutes
<result>B</result>
An air conditioner can coo the hall in 10 minutes while another takes 15 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?