diff --git a/BT-1.sol b/BT-1.sol
new file mode 100644
index 0000000..0593c9e
--- /dev/null
+++ b/BT-1.sol
@@ -0,0 +1,27 @@
+//SPDX-License-Identifier:UNLICENSED
+pragma solidity ^0.8.0;
+
+contract Bank_1{
+
+    uint16 balance = 0;
+    address public account;
+
+    constructor(){
+        account = msg.sender;
+    }
+
+
+    function checkBalance() public view returns (uint16){
+        return balance;
+    }
+
+    function deposit(uint16 amt) public payable {
+        require(amt > 0,"you cant deposit 0");
+        balance += amt;
+    }
+
+    function withdraw(uint16 amt) public payable {
+        require(balance >= amt,"balace is not enough");
+        balance -= amt;
+    }
+}
\ No newline at end of file
diff --git a/BT-2.sol b/BT-2.sol
new file mode 100644
index 0000000..89ecafd
--- /dev/null
+++ b/BT-2.sol
@@ -0,0 +1,36 @@
+//SPDX-License-Identifier:UNLICENSED
+pragma solidity ^0.8.0;
+
+contract Student_1{
+
+    struct Student{
+        uint16 id;
+        string name;
+    }
+
+    Student[] public studentData;
+
+    function addStudent(string memory name,uint16 id) public{
+        for(uint8 i=0;i<studentData.length;i++){
+            if(studentData[i].id == id){
+                revert("id already exists");
+            }
+        }
+        studentData.push(Student(id,name));
+    }
+
+    function getAll() public view returns (Student[] memory){
+        require(studentData.length > 0,"studentdata is empty");
+        return studentData;
+    }
+
+    function getLength() public view returns (uint256){
+        return studentData.length;
+    }
+
+    function getIndex(uint16 idx) public view returns (Student memory){
+        require(idx < studentData.length,"index out of bound");
+        return studentData[idx];
+    }
+
+}
\ No newline at end of file