Answer:
t = 
Step-by-step explanation:
Given that t varies inversely as the square root of u then the equation relating them is
t =
← k is the constant of variation
To find k use the condition t = 3 when u = 4, thus
k = t
= 3 ×
= 3 × 2 = 6
t =
← equation of variation
When u = 49, then
t =
= 
Step-by-step explanation:
30 days period multiply by 7 days
=210 therefore our answer is =210
Answer: 
Step-by-step explanation:
Let be "x" the lenght in feet of rope that you can buy with 30 dollars.
According to the information provided in the exercise, you can buy a piece of rope of 2 feet with 20 cents.
Remember that 
Knowing this, you can write the following proportion:

FInally, solving for "x", you get this result:
