Question:  The 2012 Olympic hunger summit was held at the official residence and office of who?

Context paragraphs:
Genadendal Residence: Genadendal Residence ] is the official residence of the President of South Africa when in office at Tuynhuys, Cape Town.  Genadendal is situated in Cape Town, Western Cape, South Africa.  It has been the official residence since 1994 when Nelson Mandela took up residence here rather than neighbouring Groote Schuur.  The building, formerly known as Westbrook, is named after the town of Genadendal – itself an Afrikaans word meaning "Valley of Mercy".

Hammerschmidt Villa: Hammerschmidt Villa (German: "Villa Hammerschmidt" ) is a villa located in the German city of Bonn that served as the primary official seat and primary official residence of the President of the Federal Republic of Germany from 1950 until 1994.  President Richard von Weizsäcker made Bellevue Palace in Berlin his primary official seat and residence in 1994.  Since 1994, the Hammerschmidt Villa has served as a secondary official seat and secondary official residence for the President.  In German, the Villa is also called the "White House of Bonn", because of its vague resemblance to the official residence of the President of the United States.

2012 Olympic hunger summit: The 2012 Olympic hunger summit was an international gathering on 12 August, the closing day of the 2012 Summer Olympics, held at 10 Downing Street London.  The event was organised largely by the Department for International Development.  It was co-hosted by Britain's prime minister, David Cameron, and by Brazil's vice president Michel Temer.  The summit was attended by several high-profile athletes and by delegates from various national governments, the United Nations, NGOs and from the private sector.

10 Downing Street: 10 Downing Street, colloquially known in the United Kingdom as Number 10, is the headquarters of the Government of the United Kingdom and the official residence and office of the First Lord of the Treasury, a post which, for much of the 18th and 19th centuries and invariably since 1905, has been held by the Prime Minister.

State House (Kenya): State House is the official residence of the President of Kenya.  It was the residence of the Prime Minister of Kenya from independence until Kenya (12 Dec 1963) transformed into a republic (12 Dec 1964).  As the Prime Minister's position was abolished, it has been the official residence of the president since then.

Singha Durbar: It was built by Shumsher immediately after accession to the post of Prime Minister.  It was initially a small private residence, but grew bigger during the construction.  Immediately after construction Shumsher sold this property to the Government of Nepal for 20 million Nepali rupee as the official residence of Prime minister.  After his death in 1929, it was used as the official residence of prime ministers of Rana dynasty except Padma Shumsher JBR, who lived in his own Bishalnagar Durbar.  The last Rana Prime minister to occupy Singha Durbar was Mohan Shumsher JBR.  Even after the fall of Rana Dynasty in 1951, Mohan used this place, but in 1953 he was ordered by His Majesty's Government to leave the palace which became a National Property.

Government House, Barbados: The Government House is the official residence and office of the Governor-General of Barbados.  It was built in the colonial days and was the residence of the Governor of Barbados.  It later continued in the role of official residence and office of the Governor-General following political independence from the United Kingdom in 1966.  Government House was once a Quaker Plantation, until it was purchased by the Imperial Government, when it acted as a replacement to The Bagatelle Great House in the Parish of St. Thomas.

11 Downing Street: 11 Downing Street (sometimes referred to as just Number 11) is the official residence of Britain's Chancellor of the Exchequer (who traditionally also has the title of Second Lord of the Treasury).  The residence, in Downing Street in London, was built alongside the official residence of the Prime Minister at Number 10 in 1682.

Eastcliff (mansion): Eastcliff is a 20-room house overlooking the Mississippi River in St. Paul, Minnesota, which serves as the official residence of the president of the University of Minnesota system.  It was first built in 1922 by local lumber magnate Edward Brooks Sr. and donated to the university by the Brooks family in 1958, beginning its service as the president's official residence in 1960 when O. Meredith Wilson took the position.  In 2000, the home was added to the National Register of Historic Places.  Today, it is the most-visited public residence in the state (outpacing the Minnesota Governor's Residence), often hosting events five days a week.  6,800 people were recorded attending 159 events in 2005.

Bute House: Bute House (Gaelic: "Taigh Bhòid") is the official residence of the First Minister of Scotland located within Charlotte Square in Edinburgh, the capital city of Scotland.  Alongside two other offices at Holyrood and at St. Andrew's House, Bute House also has a smaller office used by the First Minister when in official residence.

Supporting paragraphs: 2012 Olympic hunger summit 10 Downing Street
Answer: First Lord of the Treasury