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Q:

Alloy A contains 40% gold and 60% silver. Alloy B contains 35% gold and 40% silver and 25% copper. Alloys A and B  are mixed in the ratio of 1:4 .What is the ratio of gold and silver in the newly formed alloy is?

A) 20% and 30% B) 36% and 44%
C) 25% and 35% D) 49% and 36%

Answer:   B) 36% and 44%



Explanation:

Assume the weight of alloy a is 100 kg

\inline \fn_jvn \therefore  The weight of alloy B is 400kg

\inline \fn_jvn \therefore               Gold          silver         copper

         A       40kg          60kg          0kg

         B      140kg         160kg        100kg

      total    180kg          220kg        100kg

\inline \fn_jvn \therefore Ratio of gold and silver in new alloy =\inline \fn_jvn \frac{180}{500}:\frac{200}{500}

                                                        = 36% :44%

Q:

80 litres of diesel is required to travel 800 km using a 800 cc engine. If the volume of diesel required to cover a distance varies directly as the capacity of the engine, then how many litres of diesel is required to travel 1000 kms using 1200 cc engine ? 

A) 120 lit B) 140 lit
C) 110 lit D) 150 lit
 
Answer & Explanation Answer: D) 150 lit

Explanation:

To cover a distance of 800 kms using a 800 cc engine, the amount of diesel required = 80 litres.

=> the amount of diesel required to cover a distance of 1000 kms = 1000 x 80/800 = 100 litres

However, the vehicle uses a 1200 cc engine and it is given that the amount of diesel required varies directly as the engine capacity.

i.e., for instance, if the capacity of engine doubles, the diesel requirement will double too.

Therefore, with a 1200 cc engine, quantity of diesel required = 1200/800 x 100 = 150 litres.

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Q:

The sum of three numbers is 98. If the ratio of the first to the second is 2:3. And that of the second to the third is 5:8, then the second number is:

A) 10 B) 15
C) 20 D) 30
 
Answer & Explanation Answer: D) 30

Explanation:

Let the three parts M, N, O.
Then, M:N = 2:3 and N:O = 5:8
= (5 x 3/5) : (8 x 3/5) = 3:24/5

M:N:O = 2:3:24/5

= 10:15:24 => N = 98 x 15/49 = 30.

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Q:

Rs. 2600 is divided into three parts A, B and C. How much A is more than C if their ratio is 1/2:1/3:1/4 ?

A) 600 B) 300
C) 150 D) 75
 
Answer & Explanation Answer: A) 600

Explanation:

1/2:1/3:1/4 = 6:4:3

As the difference is 3

=> 3/13x2600 = 600

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4 307
Q:

If 6 men and 3 boys working together, can do four times as much work per hour as a man and a boy together. Find the ratio of the work done by a man and that of a boy for a given time  ?

A) 1 : 2 B) 2 : 1
C) 3 : 1 D) 1 : 3
 
Answer & Explanation Answer: A) 1 : 2

Explanation:

6M + 3B = 4(1M + 1B)
6M + 3B = 4M + 4B
2M = 1B

M/B = 1/2

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6 386
Q:

If k : l = 4 : 3 and l : m = 5 : 3, then find k : l : m ?

A) 18 : 24 : 11 B) 9 : 15 : 1
C) 20 : 15 : 9 D) 21 : 7 : 3
 
Answer & Explanation Answer: C) 20 : 15 : 9

Explanation:

Given k : l = 4 : 3
l : m = 5 : 3

Then k : l : m = 20 : 15 : 9

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