An empty bucket is put under two faucets. If one faucet is turned on alone the bucket fills in 6 minutes. If the other faucet is turned on alone the bucket fills in 4 minutes. If both are turned how many seconds will it take to fill the bucket?

Answer 1

rate of 1st bucket =1/6 buckets/minutes
rate of 2nd bucket = 1/4 buckets/minutes
combined rate= 1/6+1/4 or 5/12 buckets/minutes

time taken = 1/(5/12) = 12/5 or 2.4 minutes