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Sub 505 (Easy)|   Algebra|      
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Sajjad1994
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If, 7a/8 = (a+1)/3, then a = 21 Mar 2020, 00:34
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A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

98% (00:41) correct 2% (00:17) wrong based on 65 sessions

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If, \(\frac{7a}{8} = \frac{a + 1}{3}\), then \(a =\)

(A) 8/13

(B) 7/8

(C) 2

(D) 7/3

(E) 15
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A
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If, 7a/8 = (a+1)/3, then a = 21 Mar 2020, 05:56
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SajjadAhmad
If, \(\frac{7a}{8} = \frac{a + 1}{3}\), then \(a =\)

(A) 8/13

(B) 7/8

(C) 2

(D) 7/3

(E) 15
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Key concept: If \(\frac{a}{b}\) = \(\frac{c}{d}\), then \(ad=bc\)

Given: \(\frac{7a}{8} = \frac{a + 1}{3}\)

Cross multiply to get: \((7a)(3) = (8)(a+1)\)

Expand to get: \(21a = 8a+8\)

Subtract \(8a\) from both sides to get: \(13a = 8\)

Divide both sides by \(13\) to get: \(a = \frac{8}{13} \)

Answer: A

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If, 7a/8 = (a+1)/3, then a = 21 Mar 2020, 09:22
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Solution



Given
In this question, we are given that
    • An equation of a: 7a/8 = (a+1)/3

To find
We need to determine
    • The value of a, from the given equation

Approach and Working out
Simplifying the given equation, we get
    • 7a/8 = (a+1)/3
    Or, 21a = 8a + 8
    Or, 13a = 8
    Or, a = 8/13

Thus, option A is the correct answer.

Correct Answer: Option A
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If, 7a/8 = (a+1)/3, then a = 21 Mar 2020, 09:26
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SajjadAhmad
If, \(\frac{7a}{8} = \frac{a + 1}{3}\), then \(a =\)

(A) 8/13

(B) 7/8

(C) 2

(D) 7/3

(E) 15
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Asked: If \(\frac{7a}{8} = \frac{a + 1}{3}\), then \(a =\)

\(\frac{7a}{8} = \frac{a + 1}{3}\)
21a = 8a + 8
13a = 8
a = 8/13

IMO A
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If, 7a/8 = (a+1)/3, then a = 21 Mar 2020, 11:15
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If, \(\frac{7a}{8} = \frac{a + 1}{3}\), then \(a =\)

(A) 8/13 --> correct: \(\frac{7a}{8} = \frac{a + 1}{3}\) =>21a=8a+8 => 13a=8 =>a=8/13

(B) 7/8

(C) 2

(D) 7/3

(E) 15
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If, 7a/8 = (a+1)/3, then a = 22 Mar 2020, 01:29
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Given: 7a/8 = (a+1)/3 .. cross multiply

So, 21a = 8a+8 => a = 8/13

Option A
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If, 7a/8 = (a+1)/3, then a = 22 Mar 2020, 01:42
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\(\frac{7a}{8} = \frac{a+1}{3} \)
\(or, 21a = 8a+8,\)
\(or, a = \frac{8}{13}\)
Answer: A
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If, 7a/8 = (a+1)/3, then a = 26 Apr 2020, 04:30
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7a/8=(a+1)/3
or,21a=8a+8
or,a=8/13

correct answer A
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