diff --git a/dseki/paiza/src/C048.java b/dseki/paiza/src/C048.java
new file mode 100644
index 0000000000000000000000000000000000000000..ac5809e16f49f56af0fbdf1127b4725f9bb854f1
--- /dev/null
+++ b/dseki/paiza/src/C048.java
@@ -0,0 +1,72 @@
+import java.util.Scanner;
+
+/**
+ * タダ飲みコーヒー問題.
+ */
+public class C048 {
+  private static final int DISCOUNT_RATE_MIN = 0;
+  private static final int DISCOUNT_RATE_MAX = 100;
+  private final int coffeePrice;  // コーヒーの価格
+  private final int discountRate;  // 割引率  
+  
+  C048(final int coffeePrice, final int discountRate) {
+    this.coffeePrice = coffeePrice;
+    this.discountRate = discountRate;
+  }
+  
+  /**
+   * メインメソッド.
+   */
+  public static void main(final String[] args) {
+    final Scanner sc = new Scanner(System.in);
+    try {
+      final int coffeePrice = sc.nextInt();  // コーヒーの元値
+      final int discountRate = sc.nextInt();  // 割引率
+      final C048 c048 = new C048(coffeePrice, discountRate);
+      c048.judgeDiscountRate();
+      System.out.println(c048.getTotalPriceOfCoffee());
+    } catch (Exception e) {
+      System.out.println("例外が発生しました");
+    } finally {
+      sc.close();
+    }
+  }
+  
+  /**
+   * 存在する割引率かを判断するメソッド.
+   */
+  public void judgeDiscountRate() {
+    if (this.discountRate <= DISCOUNT_RATE_MIN ||  DISCOUNT_RATE_MAX < this.discountRate) {
+      throw new IllegalArgumentException("割引率" + this.discountRate + "%は存在しません");
+    }
+  }
+  
+  /**
+   * コーヒーに支払った合計額を返すメソッド.
+   * コーヒーから割引額を引いたものの小数点は切り捨てる。
+   * コーヒーを割引していき、0未満になれば処理終了して、合計額を返す
+   *
+   * @return コーヒーに支払った合計額を返す
+   */
+  public int getTotalPriceOfCoffee() {
+    int total = 0;
+    int coffeePriceAfterDiscount = this.coffeePrice;
+    while (coffeePriceAfterDiscount > 0) {
+      total += coffeePriceAfterDiscount;
+      coffeePriceAfterDiscount -= discountCoffeePrice(coffeePriceAfterDiscount);
+      Math.floor(coffeePriceAfterDiscount);
+    }
+    return total;
+  }
+  
+  /**
+   * コーヒーの割引額を返すメソッド.
+   *
+   * @param coffeePrice コーヒーの元値
+   * @return コーヒーの割引額を返す
+   */
+  public double discountCoffeePrice(final int coffeePrice) {
+    final double discountCoffeePrice = coffeePrice * ((double) this.discountRate / 100);
+    return discountCoffeePrice;
+  }
+}
\ No newline at end of file
diff --git a/dseki/paiza/test/C048Test.java b/dseki/paiza/test/C048Test.java
new file mode 100644
index 0000000000000000000000000000000000000000..a87d308bc81f7872ea3ecdf730b144cae26d15a6
--- /dev/null
+++ b/dseki/paiza/test/C048Test.java
@@ -0,0 +1,68 @@
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import org.junit.Test;
+
+public class C048Test {
+
+  @Test(expected = IllegalArgumentException.class)
+  public void judgementDiscountRateは割引率0だと例外が発生する() throws Exception {
+    C048 c048 = new C048(100, 0);
+    c048.judgeDiscountRate();
+  }
+
+  @Test(expected = IllegalArgumentException.class)
+  public void judgementDiscountRateは割引率101だと例外が発生する() throws Exception {
+    C048 c048 = new C048(100, 101);
+    c048.judgeDiscountRate();
+  }
+
+  @Test
+  public void discountCoffeePriceで100の10割引き価格が取得できる() {
+    C048 c048 = new C048(100, 100);
+    double expected = 100.0;
+    double actual = c048.discountCoffeePrice(100);
+    assertThat(actual, is(expected));
+  }
+
+  @Test
+  public void discountCoffeePriceで150の3割引き価格が取得できる() {
+    C048 c048 = new C048(150, 30);
+    double expected = 45.0;
+    double actual = c048.discountCoffeePrice(150);
+    assertThat(actual, is(expected));
+  }
+
+  @Test
+  public void discountCoffeePriceで100の0割引き価格が取得できる() {
+    C048 c048 = new C048(100, 0);
+    double expected = 0.0;
+    double actual = c048.discountCoffeePrice(100);
+    assertThat(actual, is(expected));
+  }
+  
+
+  @Test
+  public void getTotalPriceOfCoffeeで金額が100で割引率100のコーヒーにかかった合計の金額を取得できる() {
+    C048 c048 = new C048(100, 100);
+    double expected = 100;
+    double actual = c048.getTotalPriceOfCoffee();
+    assertThat(actual, is(expected));
+  }
+  
+  @Test
+  public void getTotalPriceOfCoffeeで金額が150で割引率30のコーヒーにかかった合計の金額を取得できる() {
+    C048 c048 = new C048(150, 30);
+    double expected = 479;
+    double actual = c048.getTotalPriceOfCoffee();
+    assertThat(actual, is(expected));
+  }
+  
+  @Test
+  public void getTotalPriceOfCoffeeで金額が300で割引率50のコーヒーにかかった合計の金額を取得できる() {
+    C048 c048 = new C048(300, 50);
+    double expected = 596;
+    double actual = c048.getTotalPriceOfCoffee();
+    assertThat(actual, is(expected));
+  }
+
+}