Question

If Jeff washes his car in 6 minutes and bob washes the same car in 8 minutes. How long does it take both of them to wash the same car?

Answer 1

3 3/7 minutes or 3.4mins

Explanation:

If Jeff washed husband car in 6 minutes and Bob washed the same car in 8 minutes , the time taken by both of them in washing the car ?

If Jeff washed the car in 6 minutes , in one minute, Jeff’s work = 1/6

If bob washed in 8mins, in one minute, bob’s work = 1/8

Add both together

1/6 + 1/8

Lcm of 6 and 8 Is 24

Divide the Lcm by the denominators and multiply the results by the numerator

We have 4+3 /24

7/24

Therefore time taken by both of them in Washing is 24/7

= 3 3/7 minutes 0r 3.4mins

Answer 2

3 3/7 or 24/7 mins

Explanation:

Let total job = X

Jeff's rate = X/6

Bob's rate = X/8

Combined rate = X/6 + X/8

(4X × 3X)/24 = 7X/24

7X/24 = X/T

T = X ÷ (7X/24)

T = X × (24/7X)

T = 24/7 mins

Shortcut:

T = product of individual times/sum of individual times

T = (6×8)/(6+8)

T = 48/14

T = 24/7

T = 3 3/7 mins