PLEASE ANSWER ALL QUESTIONS

It says something is wrong about my code for these questions

# Q0 # Read in the train.csv file and name your object train.

###### Don't forget to use the strings = T argument in read.csv().

train <- read.csv("train.csv", stringsAsFactors = TRUE)

# Q7 # Use the sum() function on a logical vector to count

###### how many homes sold for more than $350,000

###### and have "Excellent" as their kitchen quality.

sum((train$SalePrice > 350000) && (train$KitchenQual == "Ex"))

# Q9 # Use the mean() function to find the average sales price

###### for a home with kitchen quality rating of "Excellent"

###### or has a garage for more than 2 cars.

mean(train$SalePrice[(train$KitchenQual == "Ex") | (train$GarageCars > 2)])

# Q10 # Use the which() function on a logical vector to find

###### the observations number(s) for a home with a

###### kitchen quality rating of "Excellent"

###### and sales price of at most $195,000.

which ((train$KitchenQual == "Ex") && (train$SalePrice <= 195000))

The 81 column names are...

Id

MSSubClass

MSZoning

LotFrontage

LotArea

Street

Alley

LotShape

LandContour

Utilities

LotConfig

LandSlope

Neighborhood

Condition1

Condition2

BldgType

HouseStyle

OverallQual

OverallCond

YearBuilt

YearRemodAdd

RoofStyle

RoofMatl

Exterior1st

Exterior2nd

MasVnrType

MasVnrArea

ExterQual

ExterCond

Foundation

BsmtQual

BsmtCond

BsmtExposure

BsmtFinType1

BsmtFinSF1

BsmtFinType2

BsmtFinSF2

BsmtUnfSF

TotalBsmtSF

Heating

HeatingQC

CentralAir

Electrical

1stFlrSF

2ndFlrSF

LowQualFinSF

GrLivArea

BsmtFullBath

BsmtHalfBath

FullBath

HalfBath

BedroomAbvGr

KitchenAbvGr

KitchenQual

TotRmsAbvGrd

Functional

Fireplaces

FireplaceQu

GarageType

GarageYrBlt

GarageFinish

GarageCars

GarageArea

GarageQual

GarageCond

PavedDrive

WoodDeckSF

OpenPorchSF

EnclosedPorch

3SsnPorch

ScreenPorch

PoolArea

PoolQC

Fence

MiscFeature

MiscVal

MoSold

YrSold

SaleType

SaleCondition

SalePrice

PLEASE ANSWER ALL QUESTIONS