Answer:
Step-by-step explanation:
1 hour=60 min
7 hours=60×7=420 min
number of blink=420×13=5460
Answer: 285.2 kg
Step-by-step explanation:
Given
The volume of helium in the balloon is 
The density of the helium is 
Mass of the helium gas is given by the product of density and volume

Thus, the mass of gas is 285.2 kg
Answer:
a
Step-by-step explanation:
A. 25mpg $13,000 B. 45mpg $25,000 15,000 $4
15,000/25 = 600, 600x$4 = 2400 15,000/45 = 333.3, 333.3x$4 = 1333.3
2400 = 1333.3x x= 1.8
so 2 years