Answer:
2 2/11 hours
Step-by-step explanation:
Let the number of hours
Jack spent programming his app = J
Chris spent programming his app = C
Total hours if they worked together = T
Hence,
1/T = 1/3 + 1/8
Lowest Common Denominator = 34
1/T = 8 + 3/24
1/T = 11/24
Cross Multiply
T × 11 = 1 × 24
T = 24/11
T = 2 2/11 hours
Therefore, it would take them to program 2 2/11 hours to program the same app working together