Exams

Given the ratio of the circumference of front wheel  is 40 inches and back wheel is 70 inches. 

Distance covered = Circumference of the wheel × No. of Revolutions made by the wheel

If n is the number of revolutions made by back wheel, the number of revolutions made by front wheel is n+15

Distance covered by both the wheels is the same

i.e, 40*(n+15)=70n

 n=20 

                Front wheel      :      Back Wheel 

 Circumference       40      :      70 

 Revolutions           35      :      20

Distance covered  :  40×35 = 70×20 = 1400 inches.

In vulcanization, cruder rubber is heated with 3% sulphur at about for 1200C for 2-3 hours.

Vulcanised rubber is a vastly improved product.

Here in the given number puzzle, the logic is

column 2 x column 3 = column 1

3 x 3 = 9

2 x 3 = 6

Similarly,

4 x ? = 8

=> ? = 8/4 = 2.

Number of students behind Manoj in rank = (31 - 7) = 24.

So, Manoj is 25th from the bottom.

Number of students behind Satya in rank = (31 - 11) = 20.

So, Satya is 21st from the bottom.

Let the number of students in the class be 'x'.
Given if 1 is absent rest of people can be divided into 6 equal parts i.e (x-1)/6.........(1)
And given if 2 are absent rest of people can be divided into 7 equal parts i.e (x-2)/7.....(2)
From (1)&(2), we get
x-1/6 = ((x-2)/7) + 1
=> x = 37.

Here the most stable carbocation is the option (2).

Carbocations are always hungry for electrons. The stability of carbocations increases from primary to secondary to tertiary. Here, option (c) shows the most stable carbocation because it can easily withdraw electrons from two other carbon atoms and the more electronegative oxygen atom.

Carbocation stability depends on hyperconjugation. The tertiary carbocation is stabilized by electron releasing inductive effect.