Dr. Aloysius found four homogeneous mixtures, but he thinks that only three are alloys. He tests each one and determines their elemental compositions. Which of the following is not a possible alloy? A. carbon and boron
B. iron an nickel
C. aluminum and magnesium
D. iron, carbon, and nickel

A. carbon and boron

Explanation:

Carbon and boron is not an alloy.

An allow forms between metals and metals using their huge electron could.

Carbon is a non-metal, boron is a also a non-metal

Two non-metals combining together does not make an alloy.

Iron, nickel, aluminum  are all metals.

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.