GATE Questions

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An Indian boy has won the world’s largest pre-college science competition in the US in the environmental engineering category for his project on biodegradation of pesticides. Prashant Ranganathan, a 12th grader from Jamshedpur, alongwith over 20 high school students from various parts of India, participated in the Intel International Science and Engineering Fair.

The ratio of distribution should be:
21 x 15 : 15 x 35 : 35 x 21
= 315 : 525 : 735
= 3 : 5 : 7
The smallest share will be of worth:
3/15 x 52,500 = Rs. 10,500

Let the efficiencies of filling pipes is 4p and 5p respectively.

Efficiency of pipe which empty the tank = 2/3 x 9p/2 = 3p

Total work = 3p x 36 = 108p

Time to fill the tank by both the pipes = 108p/9p = 12 min.

Let a, b and c be the amounts invested in schemes X, Y and Z respectively. Then,

As we know:

Simple interest (S.I.) = PTR/100

(a × 10 × 1/100) + (b × 12 × 1/100) + (c × 15 × 1/100) = 3200

= 10a + 12b + 15c = 320000 .........(1)

Now, c = 240% of b = 12b/5 .........(2)

And, c = 150% of a = 3a/2 => a = 2/3 c = (2 × 12)b/(3 × 5) = 8b/5 .......(3)

From (1), (2) and (3), we have

16b + 12b + 36b = 320000 => 64b = 320000 => b = 5000

∴ Sum invested in Scheme Y = Rs.5000.

Let efficiency of every man and every woman be 'm' unit/day and 'w' unit/day respectively

15×12×m = 10×16×w

⇒ m/w = 8/9

Total work = 15 × 12 × 9 = 1620 units

In 2 days, total work done = 15 x 9 + 16 x 8 = 263 units

So, in 10 days work done will be = 263 × 5 = 1315 units

Remaining work will be done in = (1620-1315)/(15×8) = 5/2 days

Total days = 10 5/2 days.

Money lent to A+B = (300 + 540) = Rs. 840 

Amount received = Rs. 1032 

Interest received = Rs. 1032 - Rs.840 = Rs. 192

Interest on Rs. 300 lent to A for 1 year = 300×1×4100 = Rs. 12 

Interest on Rs.540 lent to B for 1 year = 540×6×1100 = Rs. 36 

Total yearly interest = Rs.(12+36) = Rs.48 

If interest is Rs. 48, time = 1 year 

If interest is Rs. 192, time =  192/48 = 4 years 

Except pineapple remaining all three are types of apples.

Pineapple is what kind of apple isn't an apple.

Number of words with 5 letters from given 9 alphabets formed = 95

Number of words with 5 letters from given 9 alphabets formed such that no letter is repeated is = 9P5

Number of words can be formed which have at least one letter repeated =  95 - 9P5

= 59049 - 15120

= 43929