Answer: 58, 122
Step-by-step explanation:

Answer:
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
Please give brainliest
Answer:

Step-by-step explanation:
=> 
<u>Using Formula</u> 
<u><em>Where </em></u>
a = 249
b = 248
=> 
=> 
=> 497
Answer:
No, a trapezoid is not a parallelogram. A trapezoid is defined as having Exactly two parallel sides while a parallelogram has two pairs of parallel sides.
Step-by-step explanation:
Answer:
3.75 dollars
Step-by-step explanation:
If 30 bags of popcorn = 112.50
Then what would one bag equal?
First start off by putting money/bags

Then solve.
112.50/30 = 3.75
Your answer is 3.75.
Hope this is correct, and hope it helps ^_^