Plants, animals and bacteria
Answer:
$200.0 is the cost for installing a carpet for a room that measures 12.0 feet by 15.0 feet.
Explanation:
Length of the room = l = 15.0 ft = 
Width of the room = w = 12.0 ft = 
(1 yard = 3 feet)
Area of the room = l × w = 
Cost for installing a carpet for a room = $10 per square yard
Cost for installing a carpet for a room wit area 20.0 square yard :

$200.0 is the cost for installing a carpet for a room that measures 12.0 feet by 15.0 feet.
Answer:
five half lives
Explanation:
Half-life is the time required for a quantity to reduce to half of its initial value.
How many half lives it would take to reach 3.13% form 100% of it's initial concentration:
100% - 50% : First Half life
50% - 25%: Second Half life
25% - 12.5%: Third Half life
12.5% - 6.25%: Fourth Half life
6.25% - 3.125%: Fifth Half life
This means it would take five half lives to get to 3.125% (≈ 3.13%) of it's original concentration.
Isotopes of elements where the nucleas is unstable generally release nuclear radiation. So unstable atoms