Which of the following functions represent exponential decay?

You have exponential decay if the base is a between 0 and 1 and the exponent grows as x grows, or if the base is greater than 1 and the exponents goes to negative infinity as x grows.

The only function that satisfied these requests is the second one: 1/2 is between 0 and 1, and the exponent is x itself.

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

answer: c.  

step-by-step explanation:

mixtures containing substances that get attracted to magnet can be separated using a magnet. we can separate iron from a mixture of sand and iron, as only iron attracts to the magnet.