F.1 英數! 急急急!!!!!

用戶7067

2008-10-04 1:31 am

1. A boy standing on the roof his school building of height 34 metres threw a

pebble 12 metres up. Find the distance that the pebble travelled before landing

on the playground in front of the building?

2. Carol deposited $225 in the first week of January and withdrew$130 in the s

econd week and $23 in the thord week. In the last week of the month she agai

n deposited $85. Find out her balance at the ead of the month.

3.This morning Peter's father set an alarm in his watch tp remind him taking

medicine after exactlk 6又2分1 hours. If the alarm rings at 2 p.m., find the ti

me when Peter's father set the alarm.

4. A test paper with maximum mark 100 has 8 questions carrying equal mark

s. For every wrong answer ad blank answer the student will lost 15 marks and

5 marks respectively. Find the total mark of a student who has given 5 correct

answers, 2 wrong answers and I blank answer.

唔該我想要埋條式同題解呀！ thx~

回答 (1)

用戶10012

2008-10-07 3:14 pm

✔ 最佳答案

1. Up = 12m. Down to roof level = 12m. Down to ground = 34m . Total travelled = 12 + 12 + 34 = 58m.
2.1st week = + 225. 2nd week = -130. 3rd week = -23. 4th week = + 85.
Total = + 225 - 130 - 23 + 85 = + 157.
3.
Time set to ring = 6 + 1/2 hours.
At 2pm, 6 hours earlier = 8am.
So 6 and half hours earlier = 7: 30 am. setting time to ring at 2pm.
4.
100 marks for 8 questions of equal marks, so 1 correct answer gets 100/8 = 12.5 marks.
5 correct = 5 x 12.5 = 62.5
2 wrong = - 2.5 x 2 = - 5. ( No mark means losing 12.5 already ?)
1 blank = -5 x 1 = -5.
Total = + 62.5 - 5 - 5 = 52.5.

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