Question: What vocal and instrumental duo consisting of siblings Karen (1950-1983) and Richard Carpenter (b. 1946) covered Tim Hardin's "Reason to Believe"?

Context paragraphs:
The Carpenters discography: The discography of the American pop group the Carpenters consists of twelve studio albums, two Christmas albums, two live albums, forty-six singles, and numerous compilation albums.  The duo was made up of siblings Karen (lead vocals and drums) and Richard Carpenter (keyboards and vocals).

Looking for Love (Karen Carpenter song): "Looking for Love" is a song released under Karen Carpenter's name.  It is regarded to be the first release by what was to become The Carpenters.  The music was written by Karen's brother, Richard Carpenter.  It was recorded in 1966 and released on record label Magic Lamp, a small label with a limited budget.  Even though Richard Carpenter does participate on the recording, it is printed "Karen Carpenter" on the recording contract and record label.

The Carpenters: The Carpenters were an American vocal and instrumental duo consisting of siblings Karen (1950-1983) and Richard Carpenter (b. 1946).  Producing a distinctively soft musical style, which combined Karen's contralto vocals with Richard's arranging and composition skills, they became one of the best-selling music artists of all time.  During their 14-year career, the Carpenters recorded 11 albums, 31 singles, five television specials, and a short-lived television series.

The Karen Carpenter Story: The Karen Carpenter Story is an American television film about singer Karen Carpenter and the brother-and-sister pop music duo of which she was a part, The Carpenters.  The film aired on CBS on January 1, 1989.  Directed by Joseph Sargent, it starred Cynthia Gibb as Karen Carpenter, and Mitchell Anderson as her brother, Richard Carpenter.

Tim Hardin: James Timothy Hardin (December 23, 1941 – December 29, 1980) was an American folk musician and composer.  He wrote the Top 40 hit "If I Were a Carpenter", covered by, among others, Bobby Darin, Joan Baez, Johnny Cash, The Four Tops, Robert Plant, and Johnny Rivers; his song "Reason to Believe" has also been covered by many artists, notably Rod Stewart (who had a chart hit with the song), Neil Young, and The Carpenters.  Hardin is also known for his own recording career.

Morton's Potato Chips: Morton's Potato Chips was a potato chip company popular in Texas.  This company was popular for their corn chips called Chip-Os, and for the fact that The Carpenters – a vocal and instrumental American duo, consisting of siblings Karen and Richard Carpenter – did a commercial for them in the 1970s.  Morton's was a notable potato chip company in Dallas in the 1960s and 1970s.  The Carpenters sponsored Morton's in 1971.  In addition to having bags of potato chips, Morton's also distributed tin cans of potato chips, which are available on eBay.

The Belle Brigade: The Belle Brigade is an American vocal and instrumental duo from Los Angeles, CA, consisting of siblings Barbara Gruska (born c. 1983) on guitar, drums, and vocals, and Ethan Gruska (born c. 1989) on guitar, piano, and vocals.  The duo released its first album, "The Belle Brigade", in 2011 to positive critical response.

If I Were a Carpenter (song): "If I Were a Carpenter" is a song written by Tim Hardin.  Hardin's own recording of the piece appeared on his 1967 album "Tim Hardin 2".  It was one of two songs from that release (the other being ""'Misty Roses"") performed by Hardin at Woodstock in 1969.  The song has been covered a number of times by other artists:

The Best of Tim Hardin: The Best of Tim Hardin is a compilation album by folk artist Tim Hardin, released in 1969.  All the songs are taken from "Tim Hardin 1" and "Tim Hardin 2".

Don't Make Promises: "Don’t Make Promises" was the first track on Tim Hardin's debut album "Tim Hardin 1", released in 1966.  The song, along with "Reason to Believe," was one of the two major songwriting hits from the album,

Supporting paragraphs: Tim Hardin The Carpenters
Answer: The Carpenters