3/7 part of the tank is full of water. When 42 liters of water is taken out, the tank becomes empty. The capacity of the tank is -
A
82 liters
B
66 liters
C
78 liters
D
98 liters
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Question: 3/7 part of the tank is full of water. When 42 liters of water is taken out, the tank becomes empty. The capacity of the tank is -
Solution:
Let us consider,
The tank has 7x liters of total capacity and holds 3x litres of water.
And if 42 liters of water is taken out, then the tank becomes empty.
It means 3x litres of water is taken out.
∴ 3x = 42 liters
⇒ x = 14 liters
∴ Capacity of tank = 7x = 7 × 14 = 98 liters
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Updated: 2 weeks ago
A can complete a piece of work in 6 days working 8 hours a day, and B can complete the same work in 12 days working 8 hours a day. How long will it take them to complete the work together if they work 4 hours a day?
Created: 2 weeks ago
A
6 days
B
5 days
C
10 days
D
8 days
Question: A can complete a piece of work in 6 days working 8 hours a day, and B can complete the same work in 12 days working 8 hours a day. How long will it take them to complete the work together if they work 4 hours a day?
Solution:
A can complete the work in 8 × 6 = 48 hours
1 hour's work of A = 1/48 part
B can complete the work in 8 × 12 = 96 hours
1 hour's work of B = 1/96 part
(A + B)'s 1 hour's work = (1/48) + (1/96) part
= (2 + 1)/96 part
= 3/96 part
= 1/32
∴ Time taken by (A + B) working 4 hours daily = 32/(1 × 4)
= 8 days
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Updated: 2 weeks ago
Anik alone can do a piece of work in 6 days and Bishal alone in 8 days. Anik and Bishal undertook to do it for Tk. 5400. With the help of Dinesh, they completed the work in 3 days. How much is to be paid to Dinesh?
Created: 2 weeks ago
A
Tk. 675
B
Tk. 900
C
Tk. 870
D
Tk. 780
Question: Anik alone can do a piece of work in 6 days and Bishal alone in 8 days. Anik and Bishal undertook to do it for Tk. 5400. With the help of Dinesh, they completed the work in 3 days. How much is to be paid to Dinesh?
Solution:
Anik's 1day work = 1/6
Bishal's 1 day work = 1/8
∴ (Anik + Bishal + Dinesh)'s 1 day work = 1/3
∴ Dinesh's 1 day work = (1/3) - (1/6) - (1/8) = (8 - 4 - 3)/24 = 1/24
So, Dinesh's 3 day work = 3 × (1/24) = 1/8
If Dinesh contributed 8th part of work then he will receive 8th part of total payment
∴ Dinesh should be paid = 5400 × (1/8) = Tk. 675
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Updated: 2 weeks ago
Hasan can paint 54 walls in 27 minutes. Rafiq can paint 25 walls in 10 minutes. Working together, how many walls can they paint in 20 minutes?
Created: 1 week ago
A
60 walls
B
70 walls
C
90 walls
D
100 walls
Question: Hasan can paint 54 walls in 27 minutes. Rafiq can paint 25 walls in 10 minutes. Working together, how many walls can they paint in 20 minutes?
Solution:
Hasan can paint in 1 minute = 54 ÷ 27 = 2 walls
Rafiq can paint in 1 minute = 25 ÷ 10 = 25/10 = 5/2 walls
∴ Together they can paint in 1 minute = 2 + (5/2) walls
= (4 + 5)/2 = 9/2 walls
∴ In 20 minutes, they can paint = (9/2) × 20 walls
= (9 × 20)/2
= 90 walls
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Updated: 1 week ago
