diff --git a/src/transactions.ts b/src/transactions.ts
index f1cd836..01dd0f6 100644
--- a/src/transactions.ts
+++ b/src/transactions.ts
@@ -21,8 +21,7 @@ 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((transaction) => transaction[0] === "income"); // replace empty array with what you see is fit
 }
 
 // `filterExpenseTransactions` function that:
@@ -32,8 +31,7 @@ function filterIncomeTransactions(transactions: Transaction[]): Transaction[] {
 // filterExpenseTransactions(transactions); // => [["expense", 500], ["expense", 300]]
 function filterExpenseTransactions(transactions: Transaction[]): Transaction[] {
   // write your code here...
-
-  return []; // replace empty array with what you see is fit
+  return transactions.filter((transaction) => transaction[0] === "expense"); // replace empty array with what you see is fit
 }
 
 // `calculateTotalIncome` function that:
@@ -43,8 +41,8 @@ function filterExpenseTransactions(transactions: Transaction[]): Transaction[] {
 // calculateTotalIncome(transactions); // => 3200  (1000 + 1500 + 700)
 function calculateTotalIncome(transactions: Transaction[]): number {
   // write your code here...
-
-  return -1; // replace -1 with what you see is fit
+  const filteredIncome = filterIncomeTransactions(transactions);
+  return filteredIncome.reduce((sum, array) => sum + array[1], 0); // replace -1 with what you see is fit
 }
 
 // `calculateTotalExpenses` function that:
@@ -54,8 +52,8 @@ function calculateTotalIncome(transactions: Transaction[]): number {
 // calculateTotalExpenses(transactions); // => 800  (500 + 300)
 function calculateTotalExpenses(transactions: Transaction[]): number {
   // write your code here...
-
-  return -1; // replace -1 with what you see is fit
+  const filteredExpense = filterExpenseTransactions(transactions);
+  return filteredExpense.reduce((sum, array) => sum + array[1], 0); // replace -1 with what you see is fit
 }
 
 // `calculateNetTotal` function that:
@@ -65,8 +63,9 @@ function calculateTotalExpenses(transactions: Transaction[]): number {
 // calculateNetTotal(transactions); // => 2400  (3200 - 800)
 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:
@@ -81,8 +80,7 @@ function filterSignificantTransactions(
   threshold: number
 ): Transaction[] {
   // write your code here...
-
-  return []; // replace empty array with what you see is fit
+  return transactions.filter((transaction) => transaction[1] >= threshold); // replace empty array with what you see is fit
 }
 
 export {