diff --git a/src/transactions.ts b/src/transactions.ts
index f1cd836..57cfbd4 100644
--- a/src/transactions.ts
+++ b/src/transactions.ts
@@ -21,8 +21,8 @@ const transactions: Transaction[] = [
 // filterIncomeTransactions(transactions); // => [["income", 1000], ["income", 1500], ["income", 700]]
 function filterIncomeTransactions(transactions: Transaction[]): Transaction[] {
   // write your code here...
-
-  return []; // replace empty array with what you see is fit
+  
+  return transactions.filter(element => element[0] == "income"); // replace empty array with what you see is fit
 }
 
 // `filterExpenseTransactions` function that:
@@ -33,7 +33,7 @@ function filterIncomeTransactions(transactions: Transaction[]): Transaction[] {
 function filterExpenseTransactions(transactions: Transaction[]): Transaction[] {
   // write your code here...
 
-  return []; // replace empty array with what you see is fit
+  return transactions.filter(element => element[0] == "expense"); // replace empty array with what you see is fit
 }
 
 // `calculateTotalIncome` function that:
@@ -44,7 +44,7 @@ function filterExpenseTransactions(transactions: Transaction[]): Transaction[] {
 function calculateTotalIncome(transactions: Transaction[]): number {
   // write your code here...
 
-  return -1; // replace -1 with what you see is fit
+  return transactions.filter(element => element[0] == "income").reduce((total, element) => total + element[1], 0); // replace -1 with what you see is fit
 }
 
 // `calculateTotalExpenses` function that:
@@ -55,7 +55,7 @@ function calculateTotalIncome(transactions: Transaction[]): number {
 function calculateTotalExpenses(transactions: Transaction[]): number {
   // write your code here...
 
-  return -1; // replace -1 with what you see is fit
+  return transactions.filter(element => element[0] == "expense").reduce((total, element) => total + element[1], 0); // replace -1 with what you see is fit
 }
 
 // `calculateNetTotal` function that:
@@ -66,7 +66,7 @@ function calculateTotalExpenses(transactions: Transaction[]): number {
 function calculateNetTotal(transactions: Transaction[]): number {
   // write your code here...
 
-  return -1; // replace -1 with what you see is fit
+  return calculateTotalIncome(transactions) - calculateTotalExpenses(transactions); // replace -1 with what you see is fit
 }
 
 // `filterSignificantTransactions` function that:
@@ -82,7 +82,7 @@ function filterSignificantTransactions(
 ): Transaction[] {
   // write your code here...
 
-  return []; // replace empty array with what you see is fit
+  return transactions.filter(element => element[1] >= threshold); // replace empty array with what you see is fit
 }
 
 export {