Jump to content

How this logic work? - need some explanation.


thara

Recommended Posts

At a PHP exam I sat recently I got 2 questions about variables and here I have posted it. In this questions I couldn't understand at all and couldn't select write one.

 

Can any body here, explain how this logic work.

 

This wat my question -

 

If Variable 1,2 and 3 have the values 3,5 and 7 respectively, select the correct sequence of

equations that will result in placing values 12 in variable 1 and 15 in variable 3.

(Use only ADD operator)

1) 1 + 2 = 3
2) 2 + 3 = 1
3) 3 + 2 = 3
4) 2 + 1 = 2
5) 2 + 2 = 3
6) 2 + 3 = 3

 

 

If variables 1,2 and 3 have the values 10, 15 and 20 respectively, select the correct sequence of equations that will result in placing 55 in variable 2 and 60 in variable 3.

(Use only ADD operator)

1) 3 + 3 = 1
2) 2 + 1 = 3
3) 1 + 2 = 2
4) 3 + 3 = 2
5) 1 + 3 = 3
6) 2 + 2 = 2

 

 

Any explanation are greatly appreciated.

Thank you.

Edited by thara
Link to comment
Share on other sites

1 + 2 = 3 each number in this equation is a variable. Find the equation that alters the value of the variable to the requested value.

 

1 + 2 = 3 thus is 3 + 5 and it would assign 8 to variable 3. The text is confusing because they use numbers as variable names, but if you read it literally, it makes sense.

 

The first question asks to find the equation that makes variable 1 contain value 12 which is done by equation 2 (2 + 3 = 1 <=> 5 + 7 = 12).

 

The second question to get 15 in variable 3 is done by combining (sequence) equations 5 and 3.

Edited by ignace
Link to comment
Share on other sites

Thanks for good explanation. Still it not makes 100% sense for me to select the answer to my question.

 

This was my complete question with given answers to select correct one.

1. If Variable 1,2 and 3 have the values 3,5 and 7 respectively, select the correct sequence of 
equations that will result in placing values 12 in variable 1 and 15 in variable 3.

(Use only ADD operator)

1) 1 + 2 = 3
2) 2 + 3 = 1
3) 3 + 2 = 3
4) 2 + 1 = 2
5) 2 + 2 = 3
6) 2 + 3 = 3

A. 2,4,1
B. 4,3,6
C. 2,5,6
D. 3,4,5
E. 2,3,4 
Link to comment
Share on other sites

  • 2 weeks later...

Hello i think it will be simply understandable if you put it this way.

 

Question 1) If Variable 1,2 and 3 have the values 3,5 and 7

 

like the last user said, the problem in this question is they used numbers for valuable representation. literary a valuable is a place holder for a value. so what they are saying here is if we had place holders 1,2 and 3. place holder 1holds value 3, place holder 2 holds value 5 and place holder 3 holds value 7.

 

this is how its writen in php. first of all in php valuable names have rules, one of which is theie names cant start with an integer. so we shall represent the above valuables in this way.

$one = 3;

$two = 5;

$three =7;

 

I think by now the question starts to be clear.

Link to comment
Share on other sites

  • 2 weeks later...

In my first question, still I am confusing how I get 15 for variable 3 is doing by combining equations 5 and 3.

$one = 3;
$two = 5;
$three = 7;

//equation 5
$three = $two + $two; //5 + 5 = 10, store 10 in $three

//equation 3
$three = $three + $two; //10 + 5 = 15, store 15 in $three
Link to comment
Share on other sites

Thanks for reply. Then my question is, is there any correct answer to my 1st question?

 

I think equations should be 1, 3, and 5 for this.. right?

 

1. If Variable 1,2 and 3 have the values 3,5 and 7 respectively, select the correct sequence of

equations that will result in placing values 12 in variable 1 and 15 in variable 3.

(Use only ADD operator)

1) 1 + 2 = 3
2) 2 + 3 = 1
3) 3 + 2 = 3
4) 2 + 1 = 2
5) 2 + 2 = 3
6) 2 + 3 = 3

 

A. 2,4,1
B. 4,3,6
C. 2,5,6
D. 3,4,5
E. 2,3,4

 

Link to comment
Share on other sites

  • 4 months later...

Thanks for reply. Then my question is, is there any correct answer to my 1st question?

 

I think equations should be 1, 3, and 5 for this.. right?

 

 

 

 

(correct me if i'm wrong so...) try checking it?

1. If Variable 1,2 and 3 have the values 3,5 and 7 respectively, select the correct sequence of

equations that will result in placing values 12 in variable 1 and 15 in variable 3.

(Use only ADD operator)

1) 1 + 2 = 3
2) 2 + 3 = 1
3) 3 + 2 = 3
4) 2 + 1 = 2
5) 2 + 2 = 3
6) 2 + 3 = 3

variables:  one = 3,   two = 5,  three = 7

 

 

goal: one = 12    and   three = 15

 

your answer: 1,3,5

 

check:

 

1 : one + two = three    =>     3 + 5 = 8 /// three = 8

so: one = 3,   two = 5,  three = 8

 

3:  three + two = three   =>   8 + 5 = 12  ///three = 12

so: one = 3,  two = 5,  three = 12

 

5: two + two = three  => 5 + 5 = 10 ///three = 10

so: one = 3, two = 5, three = 10 

 

/// conditions have not been met. one should be equal to 12 ( one = 12) and three should be equal to 15 (three = 15)

 

also your answer should be in the choices (i.e the a, b, c choices )

 

try using these method and see if you can find the answer (i've tried it)

Link to comment
Share on other sites

This thread is more than a year old. Please don't revive it unless you have something important to add.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.