Jack was asked by her teacher to subtract 3 from a certain number and

Question

GMATbuster's Weekly Quant Quiz#8 Ques #3 
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Jack was asked by her teacher to subtract 3 from a certain number and then divide the result by 9. Instead, she subtracted 9 and then divided the result by 3, giving an answer of 43. What would her answer have been had she worked the problem correctly?

A) 15
B) 34
C) 43
D) 51
E) 138

nitesh50 · Answer

Working backwards
43*3+9=138

Now 138-3=135/9=15

Hence ans=15 A

gmatphoru · Answer

Answer is option A: i.e. 15

Chethan92 · Answer

Let the certain number be x.

Now the correct way is (x-3)/9
but she did (x-9)/3 and got 43
Then x = 138
substituting this in (x-3)/9 = 135/9 = 15

A is the answer.

gmatphoru · Answer

(x-9)/3 =43
So, x = 138.

Using x in:
(x-3)/9
we get the Answer 15.

shibsz · Answer

Let the number be x.

Now Jack subtracted 9 from the the number and then divided by 3 to result in 43.
This can be written as : (x-9)/3=43 
=> x-9=129 
=> x=138.

So, the number is 138 and Jack was asked to subtract 3 and divide by 9. 
Her correct answer should have been => (x-3)/9 = (138-3)/9 = 135/9 = 15.

Hence, A) 15.

u1983 · Answer

Say the actual number was x .
So 43*3+9 = x
or x=138

SO, in the correct way the result should have been = (138-3)/9 =135/9 = 15 Hence ,  Ans A

Salsanousi · Answer

(X-9) / 3 = 43

X= 129 + 9 = 138

(X-3) / 9 = 135 / 9 = 15

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saukrit · Answer

she did the following to the original number X

= \frac{(X-9)}{3=43}

= x-9=129

= x=138

The actual calculation was
= \frac{(X-3)}{9}

= \frac{(135)}{9}

=15    Answer ia A

sowmiyav · Answer

Let x be the number
Intended calculation
(x-3)/9
Performed calculation=43
(x-9)/3=43
x=138

sub x in intended calculation
(x-3)/9 = (135/9)=15

option A

mishugarg · Answer

let the number be x

(x-9)/3=43
x=138

As per correct calculation , it should be (x-3)/9 = 135/9=15

ArjunJag1328 · Answer

=> x - 3/9 = 43
=> x - 9 = 129
=> x = 129 + 9
=> x = 138

138 - 3 = 135/9 = 15

Answer IMO A

Jack was asked by her teacher to subtract 3 from a certain number and

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