John can paint 60 walls in 20 minutes. Emma can paint 9 walls in 15 minutes. Working together, how many walls can they paint in 25 minutes?
A
65 walls
B
90 walls
C
75 walls
D
95 walls
উত্তরের বিবরণ
Question: John can paint 60 walls in 20 minutes. Emma can paint 9 walls in 15 minutes. Working together, how many walls can they paint in 25 minutes?
Solution:
John can paint in 1 min = 60/20 = 3 walls
Emma can paint in 1 min = 9/15 = 3/5 walls
∴ Working together they can paint in 1 min = (3 + 3/5) = 18/5 walls
∴ They can paint in 25 min = (18 × 25)/5 = 90 walls
So John and Emma can paint 90 walls together in 25 minutes.
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
P can complete a piece of work in 18 days, while Q can complete the same work in 36 days. If both P and Q work together, in how many days will they be able to complete the entire work?
Created: 2 months ago
A
18 days
B
12 days
C
36 days
D
6 days
Question: P can complete a piece of work in 18 days, while Q can complete the same work in 36 days. If both P and Q work together, in how many days will they be able to complete the entire work?
Solution:
Given that,
P can do a piece of the work in 18 days and Q can do same work in 36 days
Now,
Let the total work = LCM(18, 36) = 36
Hence, total work = 36 units
Thus,
P does each day = 36 ÷ 18 = 2 units
Q does each day = 36 ÷ 36 = 1 unit
Hence, time taken by them to finish the work together = 36 ÷ (1 + 2) = 12 days.
∴ In 12 days working together they will complete the entire work.
0
Updated: 2 months ago
৪০০ জন শ্রমিক ৩০ দিনে একটি বাঁধ তৈরি করতে পারে। একই কাজ ২০ দিনে শেষ করতে হলে কতজন অতিরিক্ত শ্রমিক প্রয়োজন?
Created: 2 weeks ago
A
১৮০ জন
B
১৪০ জন
C
২২০ জন
D
২০০ জন
প্রশ্ন: ৪০০ জন শ্রমিক ৩০ দিনে একটি বাঁধ তৈরি করতে পারে। একই কাজ ২০ দিনে শেষ করতে হলে কতজন অতিরিক্ত শ্রমিক প্রয়োজন?
সমাধান:
বাঁধ তৈরি করতে,
৩০ দিনে শ্রমিক লাগে= ৪০০ জন
∴ ১ দিনে শ্রমিক লাগে = (৪০০ × ৩০) জন
∴ ২০ দিনে শ্রমিক লাগে = (১২০০০)/২০ জন = ৬০০ জন
অতএব, অতিরিক্ত শ্রমিক প্রয়োজন হবে = (৬০০ - ৪০০) জন = ২০০ জন
0
Updated: 2 weeks ago
