1985 AJHSME Problems/Problem 8

Problem

If $a = - 2$, the largest number in the set $\{ - 3a, 4a, \frac {24}{a}, a^2, 1\}$ is

$\text{(A)}\ -3a \qquad \text{(B)}\ 4a \qquad \text{(C)}\ \frac {24}{a} \qquad \text{(D)}\ a^2 \qquad \text{(E)}\ 1$

Solution 1

Since all the numbers are small, we can just evaluate the set to be \[\{ (-3)(-2), 4(-2), \frac{24}{-2}, (-2)^2, 1 \}= \{ 6, -8, -12, 4, 1 \}\]

The largest number is $6$, which corresponds to $-3a$.

$\boxed{\text{A}}$

Solution 2

Since a is negative, some numbers will be positive and some will be negative. The positive numbers are $-3a, a^2, 1.$ We know that $a=-2$ so $1<a^2<-3a.$ Thus our answer is $\boxed{\text{A}}.$

~sanaops9

Video Solution

https://youtu.be/_rGBskmj29M

~savannahsolver

See Also

1985 AJHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 7
Followed by
Problem 9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AJHSME/AMC 8 Problems and Solutions


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