Question 691189
if one faucet fills the sink in 3 minutes and another fills it in 2 minutes,
 how long will it take both faucets to fill the sink if both are turned on together?
:
Let t = time required to fill it with both faucets on
Let the completed job = 1; (a full sink)
:
Each faucet will do a fraction of the job, the two fractions add up to 1
:
{{{t/3}}} + {{{t/2}}} = 1 
Multiply by 6 to clear the denominators, resulting in:
2t + 3t = 6
5t = 6
t = 6/5
t = 1.2 minutes working together
:
:
:
Check this 
{{{1.2/3}}} + {{{1.2/2}}} =
.4 + .6 = 1