GATE Questions

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A number is divisible by 9 only if the sum of the digits of the number is divisible by 9.

Here 86236 = 8 + 6 + 2 + 3 + 6 = 25

We must add 2 to 25 to become 27 which is divisible by 9.

The carbon arc lamp was the first widely-used type of electric light and the first commercially successful form of electric lamp.

Here are the Carbon Arc Lamp Uses :

-Super bright light, capable of lighting a large length of street or a large factory interior.

-Was the ONLY electric light available to light large areas from 1800 - 1901.

-Was cheaper to light streets with the arc lamp than gas or oil lamps.

Watson bought the book for Rs. 240 and sold to Johny at a profit of 50%.

S.P = C.P(1 + P%/100)

=> S.P for Watson = C.P for Johny = 240(1 + 50/100) = 240 x 1.5 = Rs. 360

Let Johny quoted the marked price of the book as Rs. M

We know, SP = M.P(1 - Discount(%)/100)

Here discount = 10% to Shekar,

S.P for Johny = M(1 - 10/100) = 0.9M

But Johny want to earn 25% profit,

=> S.P = C.P(1 + P%/100)

=> 0.9M = 360(1 + 25/100)

=> M = (360x1.25)/0.9

=> M = Rs. 500

Therefore, Johny should quote Rs. 500 as the marked price of the book to get 25% profit and allowing 10% discount to Shekar.

Let M, N and O worked together for x days.

From the given data,
M alone worked for 8 days
M,N,O worked for x days
N, O worked for 1 day

But given that
M alone can complete the work in 18 days
N alone can complete the work in 36 days
O alone can complete the work in 54 days

The total work can be the LCM of 18, 6, 54 = 108 units

M's 1 day work = 108/18 = 6 units
N's 1 day work = 108/36 = 3 units
O's 1 day work = 108/54 = 2 units

Now, the equation is
8 x 6 + 11x + 5 x 1 = 108
48 + 11x + 5 = 108
11x = 103 - 48
11x = 55
x = 5 days.

Hence, all M,N and O together worked for 5 days.

Average speed = Total distance / Total time.

Total distance traveled by Joel = Distance covered in the first 3 hours + Distance covered in the next 5 hours.

Distance covered in the first 3 hours = 3 x 60 = 180 miles
Distance covered in the next 5 hours = 5 x 24 = 120 miles

Therefore, total distance traveled = 180 + 120 = 300 miles.

Total time taken = 3 + 5 = 8 hours.

Average speed = 300/8 = 37.5 mph.

we know that 1 mile = 1.6 kms

=> 37.5 miles = 37.5 x 1.6 = 60 kms

Average speed in Kmph = 60 kmph.

Reduction in consumption
= P100+P X 100%
= 25100+25 X 100%
= 20%

Udaipur, a city in the state of Rajasthan which was named after the Maharana Udai Singh - II, is known for its beautiful artificial lakes around the city and lavish royal residences.

Thus, Udaipur nickname is City of Lakes in India.