ruben2navega wrote:

31 of the scientists that attended a certain workshop were Wolf Prize laureates, and 13 of these 31 were also Nobel Prize laureates. Of the scientists that attended that workshop and had not received the Wolf prize, the number of scientists that had received the Nobel Prize was 3 greater than the number of scientists that had not received the Nobel Prize. If 50 of the scientists attended that workshop, how many of them were Nobel Prize laureates?

A)11

B)18

C)24

D)29

D)36

Attachment:

matrixnobel.png [ 12.72 KiB | Viewed 832 times ]
Double matrix worked very well here.

Total attendees: 50

Total Wolf Prize winners = 31

Total who did not win a Wolf Prize: 50 - 31 =

19Total who won both Wolf and Nobel prizes: 13

Total Nobel prize winners?"Of those who attended and had not received Wolf prize . . ." (

not W column)

"the number of those who had received Nobel prize was 3 greater than the number of those who had not

x = those who won neither Wolf nor Nobel

x + 3 = those who did not win Wolf but did win Nobel

Solve for x as in diagram

2x + 3 = 19

x = 8

No W, no N = 8

No W, yes N = 11

Total the N row (Wolfram and

Nobel) + (

Nobel only):

13 + 11 = 24Answer CHope that's coherent. And helpful to some. :-)