x = √8 - √7 = 1/(√8 + √7) and y = √6 - √5 = 1/(√6 + √5) and z = √10 - 3 = 1/(√10 + 3)

As (√8 + √7) > (√6 + √5), (√8 - √7) < (√6 - √5)

As (√10 + 3) > (√8 + √7) > (√6 + √5)

z < x < y.

The boring of India’s first underwater rail tunnel under the Hooghly River for establishing metro link between Howrah and Kolkata has completed before its scheduled deadline of July 2017. The tunnel is 16.6 km long, out of which 10.8 km runs under the ground. Of this 10.8 km, 502 metres is under the water and the whole thing connects Howrah to the west and Salt lake to the east. It will have 12 stations and six will be underground. Estimated cost of the entire project is $750 million or about Rs 5,000 crores. The final commissioning of the project is expected by December 2019, following which it will be operational. The project is built by Afcons Transtonnelstroy and implemented by Kolkata Metro Railway Corporation Ltd (KMRCL).

Milk = 3/5 x 20 = 12 liters, water = 8 liters

If 10 liters of mixture are removed, amount of milk removed = 6 liters and amount of water removed = 4 liters.

Remaining milk = 12 - 6 = 6 liters

Remaining water = 8 - 4 = 4 liters

10 liters of pure milk are added, therefore total milk = (6 + 10) = 16 liters.

The ratio of milk and water in the new mixture = 16:4 = 4:1

If the process is repeated one more time and 10 liters of the mixture are removed,
then amount of milk removed = 4/5 x 10 = 8 liters.

Amount of water removed = 2 liters.

Remaining milk = (16 - 8) = 8 liters.

Remaining water = (4 -2) = 2 liters.

Now 10 lts milk is added => total milk = 18 lts

The required ratio of milk and water in the final mixture obtained

= (8 + 10):2 = 18:2 = 9:1.

Total time taken = k/40 + 2k/20 hours

= 5k/40 = k/8 hours

Average speed = 3k/(k/8) = 24 kmph.

Let the sum be Rs. 100. Then,
S.I. for first 6 months = (100 x 8 x 1) / (100 x 2) = Rs. 4
S.I. for last 6 months = (104 x 8 x 1) / (100 x 2) = Rs. 4.16
So, amount at the end of 1 year = (100 + 4 + 4.16) = Rs. 108.16
Effective rate = (108.16 - 100) = 8.16%.

I      II     III

65   58   100

65 -------- 7
100 ------ ?  => 10.769%

(385/1001) = 5/13

First Number is 5

=> Fourth number is 13 

x – y = 5

4x – 6y = 6

x = 12 y = 7