If 5 workers can paint a house in 8 hours, how long would it take 20 workers to paint the same house?
A
2 hours
B
3 hours
C
5 hours
D
1 hours
উত্তরের বিবরণ
Question: If 5 workers can paint a house in 8 hours, how long would it take 20 workers to paint the same house?
Solution:
5 workers can paint a house in 8 hours
∴ 1 worker would take = (8 × 5) hours
∴ 20 workers would take = (8 × 5)/20 hours
= 2 hours
0
Updated: 1 month ago
A can complete a work in 20 days, while B can complete the same work in 30 days. If both A and B work together, in how many days will they complete the entire work?
Created: 1 month ago
A
8 days
B
10 days
C
12 days
D
15 days
Question: A can complete a work in 20 days, while B can complete the same work in 30 days. If both A and B work together, in how many days will they complete the entire work?
Solution:
A's 1 day work = 1/20
B's 1 day work = 1/30
Together 1 day work = 1/20 + 1/30
= (3 + 2)/60 = 5/60 = 1/12
∴ Total time = 1/Combined work rate
= 1/(1/12) days
= 12 days
0
Updated: 1 month ago
P and Q together complete a piece of work in x days. If P alone completes the work in (x + 3) days and Q alone completes the piece of work in (x + 12) days, what is the value of 'x'?
Created: 2 months ago
A
8
B
6
C
12
D
4
Question: P and Q together complete a piece of work in x days. If P alone completes the work in (x + 3) days and Q alone completes the piece of work in (x + 12) days, what is the value of 'x'?
Solution:
P's 1 day's work = 1/(x + 3) part
Q's 1 day's work = 1/(x + 12) part
and (P + Q)'s 1 day's work = 1/x
ATQ,
1/(x + 3) + 1/(x + 12) = 1/x
⇒ (x + 12 + x + 3)/(x + 3)(x + 12) = 1/x
⇒ (2x + 15)/(x2 + 15x + 36) = 1/x
⇒ 2x2 + 15x = x2 + 15x + 36
⇒ 2x2 + 15x - x2 - 15x = 36
⇒ x2 = 36
∴ x = 6
0
Updated: 2 months ago
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?
Created: 1 month ago
A
10 days
B
14 days
C
18 days
D
21 days
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
