F2 MATHS

Question

Kedai Kain Meriah menerima tempahan menjahit sebanyak 150 helai alas meja dari sebuah katering. Setiap alas meja memerlukan 1 1/2jam untuk disiapkan. Kedai itu mempunyai dua orang tukang jahit dan beroperasi setiap hari dari pukul 8.00 pagi hingga pukul 7 petang dengan rehat makan selama 1 jam.

Meriah Textile Shop receives an order of 150 table cloths from a catering. Each table cloth needs 1 1/2 hours to complete. The shop has two tailors and operates every day from 8.00 a.m. until 7 p.m. with a lunch time for 1 hour.

(a) Berapakah bilangan alas meja yang dapat disiapkan dalam masa sehari? Setiap hari, tukang jahit mula menjahit pada pukul 9.00 pagi.
How many table cloths can be completed in a day? The tailors will start to sew at 9 a.m. every day.

The answer is 12

Comments

then answer 12 is wrong.

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I think that the answer means that if just one tailor can make 6 2/3 table cloths,and round off is 6 ,because has two tailors so that can make 6 times 2 that is 12 table cloths in a day.

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But this is wrong because if one of the tailor can make 6 2/3 table cloths and the 2/3 table clothes that didn’t finish can let another tailor (got two tailor) to continue finish it. so working you can see @NPL and explanation you can see me.

Answer 1

8:00a.m. 至 7p.m. 有 11个小时。

（算法：将 8:00a.m. 和 7p.m. 换成24小时计时法，所以是 0800时 和 1900时，所以相减 为11个小时）

因为 lunch time 1小时，所以 做工10小时。

1 1/2hours =（1 1/2 ✖️60）分钟

=（3/2 ✖️60）分钟 =90分钟（做一个table cloth的时间）

所以

10小时（工作时间）➗ 90分钟（做一个table cloth 的时间）=（10✖️60分钟）➗90分钟

=600分钟➗90分钟

=600/90

=6 60/90

=6 2/3（一天可生产的 table cloth）*（剩下的1/3 未完成的table cloth 下一天继续做）

因为有2个 tailor，所以一天可做 6 2/3 ✖️2=20/3 ✖️2=40/3=13 1/3个table cloths，所以应该是一天可以做 13 个 table cloths。（round off）

the answer 12 is wrong.The answer means that if just one tailor can make 6 2/3 table cloths,and round off is 6 ,because has two tailors so that can make 6 times 2 that is 12 table cloths in a day. But this is wrong because if one of the tailor can make 6 2/3 table cloths and the 2/3 table clothes that didn’t finish can let another tailor (got two tailor) to continue finish it. so working you can see @NPL and explanation you can see me.

Answer 2

operating hour in a day = (7+12) - 8 = 11 hours

Not including lunch time = 11 -1 = 10 hours

table clothes that can be produced by one tailor each day = 10 hours / (3/2 hours) = 6 2/3
table clothes that can be produced each day = 6 2/3 x 2 = 13 1/3 (about 13 per day)

Comments

等等，题目好像说有2个tailor

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哦哦好 谢谢提醒

Answer 3

150 clothes, each needs 1 1/2h, 2 tailors 

1 1/2 = 60+30 = 90min

150 x 90min / 2 tailors = 6750 min 

so, 150 clothes need 6750 min to complete

 

8am-9pm, 1h lunch

8am - 0800

7pm - 1900

1900 - 0800 = 11h

11h - 1h lunch = 10h 

10h x 60 =600min

so, 1 day, work 600min    

 

how many days are needed to sew all

6750min / (600min per day) = 11.25 days = 12 days (rounded off)