A can complete a work in 20 days, B in 30 days, and C in 60 days. A stops working 4 days before the completion of the work, and B stops 6 days before completion. C continues working alone till the end. What was the total number of days taken to complete the entire work?
A
10 days
B
14 days
C
18 days
D
21 days
উত্তরের বিবরণ
Question: A can complete a work in 20 days, B in 30 days, and C in 60 days. A stops working 4 days before the completion of the work, and B stops 6 days before completion. C continues working alone till the end. What was the total number of days taken to complete the entire work?
Solution:
Let the total work be completed in y days.
∴ A worked for (y - 4) days
So his contribution = (y - 4)/20
B worked for (y - 6) days
So his contribution = (y - 6)/30
C worked full y days, so his contribution = y/60
Therefore,
(y - 4)/20 + (y - 6)/30 + y/60 = 1
⇒ 3(y - 4) + 2(y - 6) + y = 60
⇒ 3y - 12 + 2y - 12 + y = 60
⇒ 6y - 24 = 60
⇒ 6y = 84
⇒ y = 14
∴ The total work was completed in 14 days.
0
Updated: 1 month ago
A can complete a piece of work in 36 days, B in 54 days and C in 72 days. All the three began the work together but A left 8 days before the completion of the work and B 12 days before the completion of work. Only C worked up to the end. In how many days was the work completed?
Created: 2 months ago
A
18 days
B
24 days
C
28 days
D
36 days
Question: A can complete a piece of work in 36 days, B in 54 days and C in 72 days. All the three began the work together but A left 8 days before the completion of the work and B 12 days before the completion of work. Only C worked up to the end. In how many days was the work completed?
Solution:
Let the work be completed in y days. C works for y days
Therefore, A works for (y - 8) days
B works for (y - 12) days.
According to the question,
{(y-8)/36} + {(y - 12)/54} + (y/72) = 1
⇒ 6(y - 8) + 4 (y - 12) + 3y = 216
⇒ 6y - 48 + 4y - 48 + 3y = 216
⇒ 13y = 216 + 96 = 312
⇒ y = 312/13
∴ y = 24
0
Updated: 2 months ago
In a factory, 20 people can make 20 toys in 15 days working 10 hours per day. Then, in how many days can 25 persons make 30 toys working 20 hours per day?
Created: 2 months ago
A
6 days
B
15 days
C
12 days
D
9 days
Question: In a factory, 20 people can make 20 toys in 15 days working 10 hours per day. Then, in how many days can 25 persons make 30 toys working 20 hours per day?
Solution:
Here,
M1 = 20, M2 = 25
D1 = 15, D2 = ?
T1 = 10, T2 = 20,
W1 = 20 and W2 = 30.
We know,
M1 × D1 × T1 × W2 = M2 × D2 × T2 × W1
⇒ 20 × 15 × 10 × 30 = 25 × D2 × 20 × 20
∴ D2 = 9
Thus, the required day = 9 days
0
Updated: 2 months 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
