Một xe khách từ Mỹ Đình đến Hạ Long mất 2 giờ. Một xe máy từ Hạ Long đến Mỹ Đình mất 3 giờ. Tính quãng đường từ Mỹ Đình đến Hạ Long biết vận tốc xe khách hơn vận tốc xe máy là 20 km/giờ. Nếu hai xe khởi hành cùng một lúc thì chúng gặp nhau tại một địa điểm cách Mỹ Đình bao nhiêu ki- lô- mét? Đáp số là 120 km ạ. Mk cần lời giải ạ.

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Exercise 6: Read the situations and make sentences with needn’t have. 1. George went out He took an umbrella because he thought it was going to rain. But it didn't rain. - He needn't have taken an umbrella . 2. Ann bought some eggs when she went shopping. When she got home, she found that she already had plenty of eggs. - She ……………………….. 3. A friend got angry with you and shouted at you. You think this was unnecessary'. Later you say to him/her. You ……………………….. 4. Brian had no money, so he sold his car. A few days after he won some money in a lottery. He ……………………….. 5. When we went on holiday, we took the camera with us but we didn’t use it in the end. We ……………………………………………… Exercise 7: Complete the sentences with should (have) + the verb in brackets. 1. Margaget should have passed the exam She's been studying very hard (pass) 2. You missed a great party ast night You should have come. (come) 3. We dont see you enough. You ......................and see us more often (Come) 4. I’m in a difficult position. What do you think I.......................................... ? (do) 5. I’m sorry that I didn't take your advice. I.......................................................... what you said (do) 6. I’m playing tennis with Jill tomorrow. She..........................................- she's much better than me. (win) 7. We lost the match but we .................................We were the better team (win) 8 "Is John here yet? "Not yet, but he ...................................here soon" (be) 9. I posted the letter three days ago, so it............................................................ by now. (arrive)

Exercise 5: Read the situations and use the words in brackets to write sentences with must have and can't have. Eg: 1. The phone rang but I didn't hear it (I/asleep). I must have been asleep . 2. Jane walked past me without speaking, (she/see/me). She can’t have seen me 3. The jacket you bought is very good quality, (it/very expensive) - ………………………………………………………………………….. 4. I haven't seen the people the next door for ages, (They/go away) - ………………………………………………………………………….. 5. I cant find my umbrella, (Weave/it in the restaurant last night) - ………………………………………………………………………….. 6. Don passed the exam without studying for It (me exam / very difficult) - ………………………………………………………………………….. 7. She knew everything about our plans, (she/ listen / to our conversation) - ………………………………………………………………………….. 8. Fiona did the opposite of what I asked her to do. (she/understand/what I said) - ………………………………………………………………………….. 9. When I woke up this morning, the light was on. (I forget/to turn/ it off) - ………………………………………………………………………….. 10. The lights were red but the car didn't stop, (the driver/see/the red light) - ………………………………………………………………………….. 11. I was woken up in the middle of the night by the noise next door (the neighbours/have/ a party) - …………………………………………………………………………..

Exercise 4: Rewrite the following sentences. 1/ It isn't necessary to shout.  You ............................................................................................ 2/ It wasn't necessary for them to call for help after all. They ................................................. 3/ There was no need for you to have gone to all that trouble.  You .......................................... 4/ Your house needs to be redecorated.  Your house.................................................................... 5/ It's possible that he didn't get my letter.  He might ................................................................. 6/ You needn't have bought it for me.  It wasn't ........................................................................... 7/ I'm absolutely sure that they didn't go out in that weather.  They can't ................................................................................................................................... 8/ "Why didn't you tell me about it yesterday ?"  You should .................................................... 9/ I'm sure she didn't do it on purpose.  She can't.................................................................. 10/ It's possible that your car was stolen.  Your car ................................................................ 11/ Perhaps Lan went to London.  Lan might....................................................................... 12/ It's a pity that you didn't go to see that film at the cinema last night.  You should .................................................................................................................................. 13/ "It was very careless of you to let the door open last night"  You shouldn't............................................................................................................................... 14/ Perhaps Manh is repairing his bike now.  Manh may........................................................ 15/ Perhaps they have two big houses in the suburb.  They ........................................................ 16/ You ought to have reminded me about the meeting yesterday.  Why didn't ...................................................................................................................................

Exercise 2: Choose the correct answer in each of the following sentences according to meaning and tense. 1. If I had a bicycle, (I would / I will) ride it every day. 2. George (would have gone / would go) on a trip to Chicago if he had had time. 3. Marcela didn’t come to class yesterday. She (will have had / may have had) an accident. 4. John didn’t do his homework, so the teacher became very angry. John (must have done / should have done) his homework. 5. Sharon was supposed to be here at nine o’clock. She (must have forgotten / must forget) about our meeting. 6. Where do you think Juan is today? I have no idea. He (should have slept / may have slept) late. 7. George missed class today. He (might have had / might had had) an accident. 8. Robert arrived without his notebook. He (could have lost / would have lost) it. 9. Thomas received a warning for speeding. (He should have driven / shouldn’t have driven) so fast. 10. Henry’s car stopped on the highway. It (may run / may have run) out of gas. Exercise 3: Choose between “must + have + PP” and “should + have + PP” 1. Hendry was deported for having an expired visa. He (have)____________ his visa renewed. 2. Julietta was absent for the first time yesterday. She (be)___________ sick. 3. The photos are black. The X rays at the airport (damage)___________ it. 4. Blanca got parking ticket. She (not, park)______________ in a reserved spot, since she had no permit. 5. Mary did very well on the exam. She (study)_____________ very hard. 6. Jean did very badly on the exam. She (study)_____________ harder. 7. German called us as soon as his wife had her baby. He (be)____ very proud. 8. John isn’t here yet. He (forget)______________ about our meeting. 9. Alex failed the exam. He (not, study)_____________ enough.