##### Reduction of a problem to NP-Complete

If a problem 'X' is reduced to a NP-Complete problem, does that proves that X belongs to NP?

Sumit Verma sumitverma 5 Mar 2017 02:14 am

No, We can not say anything about X.

Md. Golam Mostafa mostafarana 5 Mar 2017 03:08 pm

If 60% of the mangoes in a particular harvest had an average (arithmetic mean) wright of 350 grams and 40% of the mangoes in that harvest had an average (arithmetic mean) weight of 400 grams, what was the average (arithmetic mean) weight, in grams, of all of the mangoes in the harvest?

Virtual GATE virtualgate 6 Mar 2017 01:12 pm

Please ask you questions in the doubt section of techtud , rather than commenting on a previously asked question. This will increase the visibility of your question .

Now,

Let 60 % of mangoes weigh X grams and,

40 % of mangoes weigh Y grams

Let total number of mangoes be "n".

A/Q

$350 = {X \over 0.6n}$  ⇒  $350*0.6 = {X \over n}$   ⇒  $210 = {X \over n}$     ------------------------- (1)

$400 = {Y \over 0.4n}$   ⇒ $400*0.4 = {Y \over n}$   ⇒   $160 = {Y \over n}$     --------------------------(2)

(1) + (2)

$210 + 160 = { X + Y \over n}$

⇒ $370 = {Total Wt. \over n}$

Therefore, Average Weight of mangoes = 370 grams

Md. Golam Mostafa mostafarana 6 Mar 2017 01:31 pm

thanks