Answer:
6 hours
Step-by-step explanation:
because if they work together it will be 9 hours slower than Kelsey's time alone.
not sure if correct
Oh no my parrot is missing
Answer: 
Step-by-step explanation:
divided by
is the same thing as multiplying
by
.
The equation we get is:

With this equation, we can factor each equation:

We can cancel out like terms since they would be dividing each other:

2.52 * 27.94 = 70.4088, so not that one
94.1 * 2.5 = 235.25, so not that one
1.83 * 2.9 = 5.307, so not that one
25.07 * 5.4 = 135.378, so that one
Answer:
D. 25.07 * 5.4 = 135.378
When Serena is 10, her mom is 3*10=30. Her mom is 20 years older than Serena.
If her mom's age divided by half is equal to Serena's, then she will be twice as old as Serena.
20 + 20 = 40
20 * 2 = 40
Serena will be 20, her mom will be 40.