Answer:
6.16 hours
Explanation:
Let the number of hours that washed the car together = T
Number of hours Matthew washed = m = 14 hours
Number of hours Arianna washed = a = 11 hours
The formula to calculate how many they wash the cars together is given as
1/a + 1/m = 1/T
1/14 + 1/11 = 1/T
Lowest Common Denominator = 154
Hence:
(11 + 14)/154 = 1/T
25/154 = 1/T
Cross Multiply
154 × 1 = 25 × T
T = 154/25
T = 6.16 hours
Therefore, it will take Matthew and Arianna 6.16 hours to wash the cars together