diff --git a/controllers/controller.js b/controllers/controller.js
index fc00a20..6462770 100644
--- a/controllers/controller.js
+++ b/controllers/controller.js
@@ -1,3 +1,4 @@
+const mongoose = require('mongoose');
 const Model = require('../model/question');
 
 exports.getAge = (req, res, next) => {
@@ -93,7 +94,7 @@ exports.postRandom = (req, res, next) => {
 }
 
 exports.getMixtureAndAlligation = (req, res, next) => {
-    return Model.Mixture
+    return Model.MixtureAndAlligation
     .aggregate([
         { $sample : { size : 1 } },
         {$project : { _id : 0, _v : 0} }
@@ -112,7 +113,7 @@ exports.postMixtureAndAlligation = (req, res, next) => {
     const options = req.body.options;
     const explanation = req.body.explanation;
 
-    const mixture = new Model.Mixture({
+    const mixture = new Model.MixtureAndAlligation({
         question : question,
         answer : answer,
         options : options,
@@ -185,7 +186,7 @@ exports.postProfitAndLoss = (req, res, next) => {
 }
 
 exports.getPermutationAndCombination = (req, res, next) => {
-    return Model.Permutation
+    return Model.PermutationAndCombination
         .aggregate([
             { $sample : { size : 1 } },
             {$project : { _id : 0, _v : 0} }
@@ -204,7 +205,7 @@ exports.postPermutationAndCombination = (req, res, next) => {
     const options = req.body.options;
     const explanation = req.body.explanation;
 
-    const permutationAndCombination = new Model.Permutation({
+    const permutationAndCombination = new Model.PermutationAndCombination({
         question : question,
         answer : answer,
         options : options,
@@ -277,7 +278,7 @@ exports.postSpeedTimeDistance = (req, res, next) => {
 }
 
 exports.getSimpleInterest = (req, res, next) => {
-    return Model.SimpleAndInterest
+    return Model.SimpleInterest
         .aggregate([
             { $sample : { size : 1 } },
             {$project : { _id : 0, _v : 0} }
@@ -296,7 +297,7 @@ exports.postSimpleInterest = (req, res, next) => {
     const options = req.body.options;
     const explanation = req.body.explanation;
 
-    const simpleInterest = new Model.SimpleAndInterest({
+    const simpleInterest = new Model.SimpleInterest({
         question : question,
         answer : answer,
         options : options,
@@ -412,4 +413,34 @@ exports.postPipesAndCisterns = (req, res, next) => {
             }
             next(err)
         })
+}
+
+exports.deleteQuestion = (req, res, next) => {
+    const model = req.params.model;
+    const question = req.body.question;
+    if(model){
+       mongoose.model(model).findOneAndDelete({question : question})
+        .then(doc => {
+            if(!doc){
+                const error = new Error("Question not found");
+                error.statusCode = 404;
+                throw error;
+            }
+            res.json({
+                message : 'Question deleted successfully',
+                deletedQuestion : {
+                    question : doc.question,
+                    answer : doc.answer,
+                    options : doc.options,
+                    explanation : doc.explanation
+                }
+            });    
+        })
+        .catch(err => {
+            if(!err.statusCode){
+                err.statusCode = 500
+            }
+            next(err)
+        }); 
+    }
 }
\ No newline at end of file
diff --git a/model/question.js b/model/question.js
index b82c1f4..c158c53 100644
--- a/model/question.js
+++ b/model/question.js
@@ -23,22 +23,22 @@ const questionSchema = new Schema({
 
 const Age = mongoose.model('Age', questionSchema);
 const Calendar = mongoose.model('Calendar', questionSchema);
-const Mixture = mongoose.model('MixtureAndAlligation', questionSchema);
-const Permutation = mongoose.model('PermutationAndCombination', questionSchema);
+const MixtureAndAlligation = mongoose.model('MixtureAndAlligation', questionSchema);
+const PermutationAndCombination = mongoose.model('PermutationAndCombination', questionSchema);
 const PipesAndCistern = mongoose.model('PipesAndCistern', questionSchema);
 const ProfitAndLoss = mongoose.model('ProfitAndLoss', questionSchema);
-const SimpleAndInterest = mongoose.model('SimpleInterest', questionSchema);
+const SimpleInterest = mongoose.model('SimpleInterest', questionSchema);
 const SpeedTimeDistance = mongoose.model('SpeedTimeDistance', questionSchema);
 const Random = mongoose.model('Random', questionSchema);
 
 module.exports = { 
     Age, 
-    Calendar, 
-    Mixture, 
-    Permutation, 
+    Random,
+    Calendar,  
     PipesAndCistern,
     ProfitAndLoss, 
-    SimpleAndInterest, 
-    SpeedTimeDistance, 
-    Random 
+    SimpleInterest, 
+    SpeedTimeDistance,
+    MixtureAndAlligation, 
+    PermutationAndCombination,
 };
\ No newline at end of file
diff --git a/routes/routes.js b/routes/routes.js
index 854021a..887ed59 100644
--- a/routes/routes.js
+++ b/routes/routes.js
@@ -6,9 +6,9 @@ const validation = require('../validation/validation');
 const aptitudeController = require("../controllers/controller");
 
 //random routes
-router.get("/random", aptitudeController.getRandom);
+router.get("/Random", aptitudeController.getRandom);
 
-router.post('/random',validation.validateQuestion ,validation.handleValidationErrors, aptitudeController.postRandom);
+router.post('/Random',validation.validateQuestion ,validation.handleValidationErrors, aptitudeController.postRandom);
 
 //mixture and alligations routes
 router.get("/MixtureAndAlligation", aptitudeController.getMixtureAndAlligation);
@@ -41,8 +41,18 @@ router.get("/Calendar", aptitudeController.getCalendar);
 router.post("/Calendar",validation.validateQuestion ,validation.handleValidationErrors, aptitudeController.postCalendar);
 
 //Pipes and Cisterns routes
-router.get("/PipesAndCisterns", aptitudeController.getPipesAndCistern);
+router.get("/PipesAndCistern", aptitudeController.getPipesAndCistern);
 
-router.post("/PipesAndCisterns",validation.validateQuestion ,validation.handleValidationErrors, aptitudeController.postPipesAndCisterns);
+router.post("/PipesAndCistern",validation.validateQuestion ,validation.handleValidationErrors, aptitudeController.postPipesAndCisterns);
+
+// Speed Time Distance routes
+router.get('/SpeedTimeDistance', aptitudeController.getSpeedTimeDistance);
+
+router.post('/SpeedTimeDistance',validation.validateQuestion ,validation.handleValidationErrors, aptitudeController.postSpeedTimeDistance);
+
+//delete questions routes
+router.delete('/:model', aptitudeController.deleteQuestion);
+
+//modify questions routes
 
 module.exports = router;
diff --git a/server.js b/server.js
index 607f69b..6838bcd 100644
--- a/server.js
+++ b/server.js
@@ -23,9 +23,9 @@ app.use((error, req, res, next) => {
     const message = error.message;
     const statusCode = error.statusCode;
     if(error.field){
-        return res.json({message : message, statusCode : statusCode, field : error.field});
+        return res.status(statusCode).json({message : message, statusCode : statusCode, field : error.field});
     }
-    return res.json({message : message, statusCode : statusCode});
+    return res.status(statusCode).json({message : message, statusCode : statusCode});
 });
 
 mongoose