Algebra Problem 1

[xyz-ihs snippet=”Code2″]

[xyz-ihs snippet=”GoogleAdsenseHor”]

The Usual Way

Let the original fraction be x/y.

$latex \therefore $New Fraction = $latex \frac{2x}{y+2}$ = 2

$latex \therefore $2x = 2y + 4 or x = y + 2 …… Eq. 1

Also; $latex \frac{x^{2}}{y+2}$ = 7

$latex \therefore $ $latex \frac{x^{2}}{7}$ = y + 2 …… Eq. 2
From Eq. 1 and 2;

$latex \frac{x^{2}}{7}$ = x

$latex \therefore $ x = 7 and y = 5

$latex \therefore $ Fraction = 7/5

(Ans: 3)

Estimated Time to arrive at the answer = 60 seconds

[xyz-ihs snippet=”Code2″]

The Smart Way

Simply read the first part of the question and find those options that satisfy that condition as shown below:

$latex \frac{5}{3}$=> $latex \frac{5\times 2}{3+2}$ = $latex \frac{10}{5}$ = 2 (Satisfies the condition)

$latex \frac{4}{8}$=> $latex \frac{4\times 2}{8+2}$ = $latex \frac{8}{10}$ = $latex \frac{4}{5}$ (does not satisfy the condition)

$latex \frac{7}{5}$=> $latex \frac{7\times 2}{5+2}$ = $latex \frac{14}{7}$ = 2 (Satisfies the condition)

$latex \frac{3}{2}$=> $latex \frac{3\times 2}{2+2}$ = $latex \frac{6}{4}$ = $latex \frac{3}{2}$ (does not satisfy the condition)

$latex \frac{8}{5}$=> $latex \frac{8\times 2}{5+2}$ = $latex \frac{16}{7}$ (does not satisfy the condition)

This leaves us with options ‘1’ and ‘3’ only. Now, look at the 2nd condition. Apply this to options ‘1’ and ‘3’ only as follows:

$latex \frac{5}{3}$=> $latex \frac{5^{2}}{3+2}$ = $latex \frac{25}{5}$ = 5 (does not satisfy the condition)
Hence, answer is option ‘3’

Just to verify…c.
$latex \frac{7}{5}$=> $latex \frac{7^{2}}{5+2}$ = $latex \frac{49}{7}$ = 7 (Satisfies the condition and hence is the answer)

(Ans: 3)

Estimated Time to arrive at the answer = 15 seconds

[xyz-ihs snippet=”FreeMath”]

[xyz-ihs snippet=”Code1″]