Answer: 30g
Step-by-step explanation:
In this question (t½) of isotope is 40 days, which means that after 40 days half of the sample would have decayed and half would be left as it is.
After 40 days ( first half life) 240 /2 = 120 g decays and 120 g remains left.
After another 40 days ( two half lives or 80 days) 120 /2 = 60 g decays and 60 g remains left .
after three half lives or 120 days, 60/2 = 30g decay and 30 g of the isotope will be left.
I hope this helps you
area formula=pi.r^2
1) Area=3,14. (3,5)^2
Area=38,465
Area nearest 38,5
2) Circumference=2pi.r
Circumference=2.3,14.3,5
Circumference=21,98
Circumference nearest 22
So, ($299.95)(. 30) = $89.99
$299.95 - $89.99= $209.96
($209.96)(.05)=$10.50
$209.96 + $10.50 = $220.46
No, she can't afford it
