Job Roles

6-3 = 3 9-4 = 5 (3x5=15) 15=O
7-2 = 5 7-3 = 4 (5x4=20) 20=T
9-6 = 3 5-1 = 4 (3x4=12) 12=L

Similarly, 4-1 = 3 8-5 = 1 (3x1=3) 3=C

Initialy from left 7th = kumar
from right 9th = pawan
Interchange kumar = 11th from left, from right kumar = 9th;
11+8 = 19;
8 is 1,2,3,4,5,6,7(pawan),8,9,10,11(kumar),12,13,14,15,16,17,18,19;
simply count the 9th place from right we will get total as 19.

Let the number of apples in each tree of the 5 farmers be a, b, c, d,e respectively. Therefore total no of apples are 7a, 9b, 11c, 13d and 14e respectively.

Given,
7a+1 = 9b+3 = 11c-1 = 13d+3 = 14e-6 = x

9b+3 = 13d+3
===> 9b = 13d
so take b = 13 and d = 9

9b+3 = 9*13+3 = 120
ie, x=120

substituting
7a+1 = 120
7a = 119
a = 17

11c-1 = 120
11c = 121
c=11

14e-6 = 120
14e = 126
e = 9

Yields per tree in the orchards of d 3rd & 4th farmers= 11,9

Let Price be Rs.100

1st CASE:

Then 100 x 70/100 = 70
=> price after discount = 100-70 = Rs.30

2nd CASE:

Then 100 x 40/100 = 40
=> price after discount = 100-40 = Rs.60
then
60 x 30/100 = 18
=> price after 2 consequent discount = 60-18 = Rs.42

=>from 1 and 2 cases, 70% discount is better.

As from the given conditions;
Order is
N O P Q R S T
Here the student standing in the middle is 'Q'.

My only son's sister is my daughter
father of my daughter is me only
her brother means she is my 'sister'.

If virus is K in 1hr i.e 60 min
then in 57 min it was K/2 as it doubles every 3 minutes
=> In 54 min it was K/4.
At 54 minutes it was K/4.

There are lots of ways to solve the issue of callback hells:

1. Modularization: break callbacks into independent functions
2. Use a control flow library, like async
3. Use generators with Promises
4. Use async/await (note that it is only available in the latest v7 release and not in the LTS version)