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A dye company received an order of 400 liters of black dye and 360 liters of brown dye. It has two machines X and Y to make these dyes. X takes 4 hours to make 16 liters of black dye and 3 hours to make 9 liters of brown dye. Y takes 4 hours to make 12 liters of black dye and 3 hours to make 12 liters of brown dye. If the company has to deliver the order in 93 hours, the delivery will be delayed by at least

A)\(15/7\) Hours
B) \(16/7\) Hours
C) \(18/7\) Hours
D) \(19/7\)Hours
E) \(20/7\) Hours
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A dye company received an order of 400 liters of black dye and 360 liters of brown dye. It has two machines X and Y to make these dyes. X takes 4 hours to make 16 liters of black dye and 3 hours to make 9 liters of brown dye. Y takes 4 hours to make 12 liters of black dye and 3 hours to make 12 liters of brown dye. If the company has to deliver the order in 93 hours, the delivery will be delayed by at least

A)\(15/7\) Hours
B) \(16/7\) Hours
C) \(18/7\) Hours
D) \(19/7\)Hours
E) \(20/7\) Hours

Merging topics. Please search before posting.
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Bunuel
Rocky1304
A dye company received an order of 400 liters of black dye and 360 liters of brown dye. It has two machines X and Y to make these dyes. X takes 4 hours to make 16 liters of black dye and 3 hours to make 9 liters of brown dye. Y takes 4 hours to make 12 liters of black dye and 3 hours to make 12 liters of brown dye. If the company has to deliver the order in 93 hours, the delivery will be delayed by at least

A)\(15/7\) Hours
B) \(16/7\) Hours
C) \(18/7\) Hours
D) \(19/7\)Hours
E) \(20/7\) Hours

Merging topics. Please search before posting.

Bunuel why is this question in DS when it is clearly a PS?
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Bunuel
Rocky1304
A dye company received an order of 400 liters of black dye and 360 liters of brown dye. It has two machines X and Y to make these dyes. X takes 4 hours to make 16 liters of black dye and 3 hours to make 9 liters of brown dye. Y takes 4 hours to make 12 liters of black dye and 3 hours to make 12 liters of brown dye. If the company has to deliver the order in 93 hours, the delivery will be delayed by at least

A)\(15/7\) Hours
B) \(16/7\) Hours
C) \(18/7\) Hours
D) \(19/7\)Hours
E) \(20/7\) Hours

Merging topics. Please search before posting.

Bunuel why is this question in DS when it is clearly a PS?

Moved to the PS forum. Thank you.
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cleetus
A dye company received an order of 400 litres of black dye and 360 litres of brown dye. It has two machines (X and Y) to make these dyes. X takes 4 hours to make 16 litres of black dye and 3 hours to make 9 litres of brown dye. Y takes 4 hours to make 12 litres of black dye and 3 hours to make 12 litres of brown dye. If the company has to deliver the order in 93 hours, its delivery will be delayed by at least

(1) 2.5 hrs
(2) 2 2/7 hrs
(3) 2 4/7 hrs
(4) 2 5/7 hrs

Attachment:
gma.jpg

in 90 hrs Y completes total 360 liters of brown dye order.
in 90 hrs X completes 360 liters of 400 liter black dye order
X's black dye rate is 4 lph
Y's black dye rate is 3 lph
let h=total hrs for order
(h-90)(7 lph)=40 liters
h=95 5/7 hrs
95 5/7-93= 2 5/7 hrs
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GyanOne
X can make 4 L/hr of black dye but only 3 L/hr of brown dye.
Y can make 4 L/hr of brown dye but only 3 L/hr of black dye.

Therefore let X make the black dye and Y make the brown dye.

In 93 hours, X would have made 93*4 = 372 L of black dye.
In 90 hours, Y would have made 90*4 = 360 L of brown dye. For the next 3 hours, it can make black dye as the brown dye is done.
So in 93 hours, total amount of black dye made = 372 L + 3*3 L = 381 L of black dye.

Amount of black dye remaining = 19 L
Rate of production of black dye = 3 L/hr (Y) + 4 L/hr (X) [as both are working on producing black dye now] = 7 L /hr
Amount of extra time required = 19/7 hours = 2 5/7 hours

Option (4) [or (D) in the usual form] is correct.

The approach on this one is giving me a headache. There are many possibilities as to how work can be done in this question.

What I did was that I involved both the machines together on one type of paint one time. So 7 liters in an hour of brown and then 7 liters an hour for black. The total came a lot more. Then I saw your approach and it worked better. How do we decide on questions such as these? I thought that time is minimized when work is maximized.
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Given: A dye company received an order of 400 litres of black dye and 360 litres of brown dye. It has two machines (X and Y) to make these dyes. X takes 4 hours to make 16 litres of black dye and 3 hours to make 9 litres of brown dye. Y takes 4 hours to make 12 litres of black dye and 3 hours to make 12 litres of brown dye.

Asked: If the company has to deliver the order in 93 hours, its delivery will be delayed by at least

To make 400 litres of black dye, it will take minimum 400*4/16 = 100 hours using machine X.
To make 360 litres of brown dye, it will take minimum 360*3/12 = 90 hours using machine Y.

In 90 hours, machine X & machine Y will produce
360 litres of brown dye & 360 litres of black dye.

Remaining work = 400 -360 = 40 litres of black dye.

Machine X & Machine Y will produce = 16/4 + 12/4 = 4 + 3 = 7 litres of black dye/hour

Time required = 40/7 = 5 5/7 hours

Total time required = 90 + 5 5/7 = 95 5/7 hours

Minimum delay = 95 5/7 - 93 = 2 5/7 hours

IMO D
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