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?
A
Tk. 1200
B
Tk. 1250
C
Tk. 1300
D
Tk. 1380
উত্তরের বিবরণ
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
0
Updated: 1 month ago
Rahim and Karim can finish a work together in 6 hours. If Rahim takes 3 times as long as Karim to finish the job alone, how long will Karim take to finish the job alone?
Created: 1 month ago
A
9 hours
B
8 hours
C
12 hours
D
15 hours
Question: Rahim and Karim can finish a work together in 6 hours. If Rahim takes 3 times as long as Karim to finish the job alone, how long will Karim take to finish the job alone?
Solution:
ধরি, করিম একা কাজটি শেষ করতে সময় নেয় = x ঘন্টা
রহিম একা কাজটি শেষ করতে সময় নেয় = 3x ঘন্টা
এখন,
করিমের 1 ঘন্টার কাজের পরিমাণ = 1/x অংশ
রহিমের 1 ঘন্টার কাজের পরিমাণ = 1/(3x) অংশ
তারা একসাথে 1 ঘন্টায় কাজ করতে পারে = (1/x) + 1/(3x)
= (3+1)/(3x)
= 4/(3x) অংশ
একসাথে কাজটি শেষ করতে সময় লাগে = 6 ঘন্টা
অর্থাৎ, 6 ঘন্টায় তারা পুরো 1টি কাজ শেষ করে
তাহলে,
(4/3x) × 6 = 1
⇒ 24/(3x) = 1
⇒ 8/x = 1
⇒ x = 8
∴ করিমের কাজটি একা শেষ করতে 8 ঘন্টা সময় লাগবে।
0
Updated: 1 month ago
If A and B can complete a work together in 10 days, B and C together in 15 days, and A and C together in 12 days, then in how many days can B alone complete the work?
Created: 1 month ago
A
24 days
B
48 days
C
54 days
D
36 days
Question: If A and B can complete a work together in 10 days, B and C together in 15 days, and A and C together in 12 days, then in how many days can B alone complete the work?
Solution:
মনে করি,
সম্পূর্ণ কাজ = 1 অংশ
∴ (A + B) একদিনে করে = 1/10 অংশ। ..........(1)
(B + C) একদিনে করে = 1/15 অংশ। ..........(2)
(A + C) একদিনে করে = 1/12 অংশ। ..........(3)
(1), (2), (3) যোগ করে পাই,
2 × (A + B + C) = (1/10) + (1/15) + (1/12)
⇒ 2 × (A + B + C) = (6 + 4 + 5)/60 = 15/60
⇒ 2 × (A + B + C) = 1/4
⇒ (A + B + C) = 1/8
∴ A, B এবং C একসাথে একদিনে করে = 1/8 অংশ।
(A + B + C) একসাথে একদিনে করে 1/8 অংশ।
(A + C) একসাথে একদিনে করে 1/12 অংশ।
∴ B-এর একদিনের কাজ = 1/8 - 1/12
= (3 - 2)/24
= 1/24
অর্থাৎ,
B সম্পূর্ণ কাজ করে = (1 ÷ 1/24) = 24 দিনে
0
Updated: 1 month ago
X can complete a work in 12 days, and Y alone can do it in 18 days. They work together for 6 days, and Z completes the remaining work in 3 days. If the total payment for the work is Tk. 600, how much should Z get?
Created: 1 month ago
A
Tk. 75
B
Tk. 90
C
Tk. 100
D
Tk. 120
Question: X can complete a work in 12 days, and Y alone can do it in 18 days. They work together for 6 days, and Z completes the remaining work in 3 days. If the total payment for the work is Tk. 600, how much should Z get?
সমাধান:
X-এর একদিনের কাজ = 1/12
Y-এর একদিনের কাজ = 1/18
X ও Y একসাথে ৬ দিন কাজ করে:
= 6 × (1/12 + 1/18)
= 6 × {(3 + 2)/36} = 6 × (5/36) = 30/36 = 5/6
∴ বাকি কাজ = 1 − 5/6 = 1/6
Z এই 1/6 কাজ ৩ দিনে করেছে, অর্থাৎ Z-এর কাজ = 1/6
X-এর কাজ = 6 × 1/12 = 1/2
Y-এর কাজ = 6 × 1/18 = 1/3
Z-এর কাজ = 1/6
তাহলে অনুপাত = 1/2 : 1/3 : 1/6
= 3 : 2 : 1
মোট টাকা = 600
Z-এর অংশ = 1/(3+2+1) = 1/6
∴ Z পাবে = 600 × (1/6) = 100 টাকা
0
Updated: 1 month ago
