Table:
0
A
B
C
D
E
F
G
H
1
President
Date of birth
Date of inauguration
Age at inauguration
End of term
Length of retirement
Date of death
Lifespan
2
Prasad, Rajendra Rajendra Prasad
1884-12-03 3 December 1884
26January1950
65-054 65years, 54days
13May1962
0,291 days
1963-02-28 28 February 1963
days (78years, 87days)
3
Radhakrishnan, Sarvepalli Sarvepalli Radhakrishnan
1888-09-05 5 September 1888
13May1962
73-250 73years, 250days
13May1967
2,896 days
1975-04-17 17 April 1975
days (86years, 224days)
4
Hussain, Zakir Zakir Hussain
1897-02-08 8 February 1897
13May1967
70-094 70years, 94days
3May1969
0,000 N/A
1969-05-03 3 May 1969
days (72years, 84days)
5
Giri, V. V. V.V. Giri
1894-08-10 10 August 1894
24August1969
75-014 75years, 14days
24August1974
2,130 days
1980-06-23 23 June 1980
days (85years, 318days)
6
Ahmed, Fakhruddin Fakhruddin Ahmed
1905-05-13 13 May 1905
24August1974
69-103 69years, 103days
11February1977
0,000 N/A
1977-02-11 11 February 1977
days (71years, 274days)
7
Reddy, Neelam Neelam Reddy
1913-05-19 19 May 1913
25July1977
64-067 64years, 67days
25July1982
5,060 days
1996-06-01 1 June 1996
days (83years, 13days)
8
Singh, Zail Zail Singh
1916-05-05 5 May 1916
25July1982
66-081 66years, 81days
25July1987
2,710 days
1994-12-25 25 December 1994
days (78years, 234days)
9
Venkataraman, Ramaswamy Ramaswamy Venkataraman
1910-12-04 4 December 1910
25July1987
76-233 76years, 233days
25July1992
6,030 days
2009-01-27 27 January 2009
days (98years, 54days)
10
Sharma, Shankar Shankar Dayal Sharma
1918-08-19 19 August 1918
25July1992
73-341 73years, 341days
25July1997
0,884 days
1999-12-26 26 December 1999
days (81years, 129days)
11
Narayanan, K. R. K.R. Narayanan
1920-10-27 27 October 1920
25July1997
76-271 76years, 271days
25July2002
1,203 days
2005-11-09 9 November 2005
days (85years, 13days)
12
Kalam, A. P. J. A.P.J.Abdul Kalam
1931-10-15 15 October 1931
25July2002
70-283 70years, 283days
25July2007
0, 2383 days
2014-02-1
days (82years, 109days)
13
Patil, Pratibha Pratibha Patil
1934-12-19 19 December 1934
25July2007
72-218 72years, 218days
25July2012
0, 556 days
2014-02-1
days (79years, 44days)
14
Mukherjee, Pranab Pranab Mukherjee
1934-12-19 11 December 1935
25July2012
76years, 227days
Incumbent
0,000 Incumbent
2014-02-1
days (78years, 52days)
15
President
Date of birth
Date of inauguration
Age at inauguration
End of term
Length of retirement
Date of death 25-7-2012
Lifespan

Questions and formulas:
Question: What was the date of the inauguration in the row with an entry of lifespan in the lifespan column?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,H1="lifespan"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H15,H2:H15="lifespan"),3))
Level: medium
Question: What was the date of death entry in the row that has a date of inauguration entry of date of inauguration?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,C1="date of inauguration"),7))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H15,C2:C15="date of inauguration"),7))
Level: medium
Question: What is the length of retirement for president Sharma, Shankar Shankar Dayal Sharma?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,A1="sharma, shankar shankar dayal sharma"),6))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H15,A2:A15="sharma, shankar shankar dayal sharma"),6))
Level: medium