If 8 men or 12 women can complete a work in 40 days, how many days would it take 20 men and 18 women to complete twice the work?
A
20 days
B
24 days
C
16 days
D
30 days
উত্তরের বিবরণ
Question: If 8 men or 12 women can complete a work in 40 days, how many days would it take 20 men and 18 women to complete twice the work?
Solution:
Here,
8 men = 12 women
∴ 1 man = 12/8 = 3/2 women
∴ 20 men = 20 × 3/2 = 30 women
∴ 20 men and 18 women together = 30 + 18 = 48 women
12 women can complete the work in 40 days
∴ 1 woman can complete the work in 40 × 12 = 480 days
∴ 48 women can complete the work in 480/48 = 10 days
Hence, to do twice the work, the time needed = 10 × 2 = 20 days
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Updated: 1 month ago
Rafi alone can complete a work in 10 days and Tareq alone can complete it in 15 days. Rafi and Tareq undertook to complete the work for Tk. 7500. With the help of Salman, they finished the work in 5 days. How much should Salman be paid?
Created: 1 month ago
A
Tk. 1200
B
Tk. 1250
C
Tk. 1300
D
Tk. 1380
Question: Rafi alone can complete a work in 10 days and Tareq alone can complete it in 15 days. Rafi and Tareq undertook to complete the work for Tk. 7500. With the help of Salman, they finished the work in 5 days. How much should Salman be paid?
Solution:
Rafi's 1 day work = 1/10
Tareq's 1 day work = 1/15
Rafi + Tareq + Salman's 1 day work = 1/5
∴ Salman's 1 day work = 1/5 - (1/10 + 1/15)
= (6 - 3 - 2)/30
= 1/30
Salman's 5 days work = 5 × 1/30 = 1/6
Salman completed 1/6 of the total work.
∴ He should be paid 1/6 of Tk. 7500
∴ Salman’s payment = 7500 × 1/6 = Tk. 1250
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Updated: 1 month ago
A canteen requires 105 kgs of wheat for a week. How many kgs of wheat will it require for 58 days?
Created: 2 months ago
A
840 kgs
B
950 kgs
C
620 kgs
D
870 kgs
Question: A canteen requires 105 kgs of wheat for a week. How many kgs of wheat will it require for 58 days?
Solution:
For 7 days it is required = 105 kgs
∴ For 1 days it is required = (105/7) kgs
∴ For 58 days it is required = (105 × 58)/7 = 870 kgs
∴ 870 kilograms of wheat will be required for 58 days.
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Updated: 2 months ago
Rafi and Shafi can paint a room in 4 days. Shafi can do it alone in 6 days. How many days will Rafi take to paint the room alone?
Created: 1 month ago
A
12 days
B
10 days
C
15 days
D
9 days
Question: Rafi and Shafi can paint a room in 4 days. Shafi can do it alone in 6 days. How many days will Rafi take to paint the room alone?
Solution:
ধরা যাক,
Rafi একা কাজটি করতে x দিন সময় নেন।
∴ Rafi-র 1 দিনের কাজ = 1/x
∴ Shafi-র 1 দিনের কাজ = 1/6 (কারণ সে একা ৬ দিনে কাজটি করে)
তারা দুজনে মিলে ৪ দিনে কাজ শেষ করে।
∴ তাদের 1 দিনের একত্রে কাজ = 1/4
এখন,
(1/x) + (1/6) = 1/4
⇒ (6 + x) / (6x) = 1/4
⇒ 4(6 + x) = 6x
⇒ 24 + 4x = 6x
⇒ 24 = 6x - 4x = 2x
⇒ x = 24 / 2 = 12
∴ Rafi একা কাজটি করতে 12 দিন সময় নেবে।
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Updated: 1 month ago
