40%

D

x     = 1/2 + 3/4

x     = 5/4

12m2

a,<

b,>

c,=

d,<

Theo đầu bài thì tổng của tất cả số HS và tất cả số HS và 1/2 số HS và 1/4 số HS của lớp sẽ bằng: 100 - 1 = 99 (em)

Để tìm được số HS của lớp ta có thể tìm trước 1/4 số HS cả lớp.

Giả sử 1/4 số HS của lớp là 1 em thì cả lớp có 4 HS

Vậy: 1/4 số HS của lứop là: 4 : 2 = 2 (em).

Suy ra tổng nói trên bằng : 4 + 4 + 2 + 1 = 11 (em)

Nhưng thực tế thì tổng ấy phải bằng 99 em, gấp 9 lần 11 em (99 : 11 = 9)

Suy ra số HS của lớp là: 4 x 9 = 36 (em)

Thử lại: 36 + 36 = 36/2 + 36/4 + 1 = 100

Đáp số: 36 học sinh.

Once, when I was at my grandmother's house in the suburbs, I looked up at the sky. That night was truly memorable for me. That sky was not like the sky I saw when I was in the city, it could be seen very clearly from a distance. I sat watching the sky with my grandmother beside me telling me stories about the stars. I saw a lot of stars twinkling in the sky. It was very bright and I also saw the full moon. I felt comfortable and peaceful as I watched the night sky

Once, when I was at my grandmother's house in the suburbs, I looked up at the sky. That night was truly memorable for me. That sky was not like the sky I saw when I was in the city, it could be seen very clearly from a distance. I sat watching the sky with my grandmother beside me telling me stories about the stars. I saw a lot of stars twinkling in the sky. It was very bright and I also saw the full moon. I felt comfortable and peaceful as I watched the night sky

Once, when I was at my grandmother's house in the suburbs, I looked up at the sky. That night was truly memorable for me. That sky was not like the sky I saw when I was in the city, it could be seen very clearly from a distance. I sat watching the sky with my grandmother beside me telling me stories about the stars. I saw a lot of stars twinkling in the sky. It was very bright and I also saw the full moon. I felt comfortable and peaceful as I watched the night sky.

Once, when I was at my grandmother's house in the suburbs, I looked up at the sky. That night was truly memorable for me. That sky was not like the sky I saw when I was in the city, it could be seen very clearly from a distance. I sat watching the sky with my grandmother beside me telling me stories about the stars. I saw a lot of stars twinkling in the sky. It was very bright and I also saw the full moon. I felt comfortable and peaceful as I watched the night sky.