Note: I'm new to R. Please be kind or don't reply! ;)

Got a dataset in .txt file format, which I loaded to variable "allData".

In this data set if I look for a certain condition eg: # of Male candidate, it works..

```
allMale <- (allData[,10] == " Male")
length(allMale[allMale==TRUE]) 

```

if I look for another condition eg: # of candidate with " <=50K" value, it works as well.. 

```
#allBelow50 <- (allData[,15] == " <=50K")
#length(allBelow50[allBelow50==TRUE])

```

But, if I combined both conditions it doesn't work!

```
allMaleBelow50 <- (allData[,10] == " Male" && allData[,15] == " <=50K")
length(allMaleBelow50[allMaleBelow50==TRUE])

```

End goal: from a data set (contains multiple column) I need the number of candidate that satisfies 2 or more conditions.

Thank you