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 weeks ago
If 6 men can build a wall in 8 days, how many days will 12 men take to build the same wall?
Created: 1 week ago
A
4 days
B
6 days
C
8 days
D
10 days
Question: If 6 men can build a wall in 8 days, how many days will 12 men take to build the same wall?
Solution:
6 জন লোক একটি দেয়াল 8 দিনে তৈরি করতে পারে।
1 জন লোক সেই দেয়াল তৈরি করতে লাগবে = (8 × 6) দিন
12 জন লোক সেই দেয়াল তৈরি করতে লাগবে = (8 × 6)/12 দিন
= 4 দিন
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Updated: 1 week ago
A man can do a work in 20 days and a woman in 15 days. If they work on it together for 5 days, then the fraction of the work that is left-
Created: 2 weeks ago
A
8/15
B
1/12
C
5/12
D
None of these
Question: A man can do a work in 20 days and a woman in 15 days. If they work on it together for 5 days, then the fraction of the work that is left-
Solution:
Man's 1 day's work = 1/20
Woman's 1 day's work = 1/15
∴ (Man + woman)'s 1 day's work = (1/20) + (1/15) = (3 + 4)/60 = 7/60
∴ (Man + woman)'s 5 day's work = (7/60) × 5 = 7/12
Thus, Remaining work = 1 - (7/12) = (12 - 7)/12 = 5/12
∴ The fraction of the work that is left = 5/12
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Updated: 2 weeks ago
A worker earns Tk. 300 on the first day and spends Tk. 150 on the second day, earns Tk. 300 on the third day and again spends Tk. 150 on the fourth day, and so on. On which day would he have had Tk. 1500?
Created: 1 week ago
A
16th day
B
17th day
C
19th day
D
21st day
Question: A worker earns Tk. 300 on the first day and spends Tk. 150 on the second day, earns Tk. 300 on the third day and again spends Tk. 150 on the fourth day, and so on. On which day would he have had Tk. 1500?
Solution:
1ম দিনে আয় = 300 টাকা
2য় দিনে ব্যয় = 150 টাকা
∴ প্রতি 2 দিনে জমা হয় = 300 - 150 = 150 টাকা
শুধু 1ম দিনে আয় করায় হাতে থাকে = 300 টাকা
অতএব, 1500 - 300 = 1200 টাকা আরও জমা করতে হবে।
150 টাকা জমা হয় 2 দিনে,
∴ 1200 টাকা জমা হয় = (2 × 1200)/150 = 16 দিনে
অর্থাৎ, 16 দিনের শেষে জমা থাকবে = 1200 টাকা
17-তম দিনে আবার আয় হবে = 300 টাকা
∴ মোট সঞ্চয় হবে = 1200 + 300 = 1500 টাকা
∴ 17-তম দিনে তার কাছে মোট 1500 টাকা জমা থাকবে।
0
Updated: 1 week ago
