user-avatar
ndkhoa277
2 năm trước
Một bể nước có 2 vòi: vòi A chảy vào bể và vòi B tháo nước ra . Khi bể không có nước nếu mở vồi A trong 5 giờ rồi khóa lại mở vòi B trong 2 giờ thì lượng nước còn lại chỉ là 2/5 bể .còn nếu mở Hai vòi cùng một lúc thì phải sau 20 giờ mới đầy bể. tính thời gian chỉ vòi A chảy vào đến khi đầy bể và thời gian vòi B tháo hết nước ở bể từ khi bể đầy cho đến khi cạn nước
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

viết lại câu + công thức viết lại của mẫu câu đó 1. the bridge which was designed by French architects .It is very nice => the bridge 2. It was a kind of accident .Nobody was really to blame for it => It was 3. Mary didn't wear the raincoat . That's why she got a cold => If 4. she is in poor heath conditions . She can' take part in the competition => If she 5. the singer called for donations for victims of floods and landslide .she was praised for it => the singer was 6. the girl had made a lot of nonsense videos . she was criticized for that => the girl was 7. she felt sleepy an tired . she tried to complete her assignment => in spite of 8. she is in a lot of trouble .she is still strong to overcome it => she has 9. she began to read thr book 3 days ago . he hasn't finished it => she has 10. she prepared for dinner . then, she went to her evening class => after 11. the last person to leave the room must turn off the lights => the last person 12. passengers who traveled on this bus bought their tickets in book => passengers 13.we bought two bicycles . neither of them worked well => we bought

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team