Question: Johnny Herbert competed using the Stewart SF3 and the Mazda 787B for what activity?

Context paragraphs:
Stewart Grand Prix: Stewart Grand Prix was a Formula One constructor and racing team formed by three times Formula One champion Jackie Stewart and his son Paul Stewart in 1996.  The team competed in F1, as the Ford works-supported team, for only three seasons, from 1997 to 1999.  The 1999 season was by far its strongest, yielding one win (Johnny Herbert at the European Grand Prix) and one pole position (Rubens Barrichello at the French Grand Prix) en route to finishing fourth overall in the Constructors Championship.

Changan Ford Mazda: Changan Ford Mazda (officially Changan Ford Mazda Automobile Co., Ltd.) was an automotive manufacturing company headquartered in Chongqing, China and a joint venture between Changan Automobile, Ford Motor Company and Mazda.  Its principal activity was the manufacture and sale of Ford and Mazda branded passenger cars in China.

Mazda 787B: The Mazda 787 and its derivative 787B are Group C sports prototype racing cars that were built by Mazda for use in the World Sportscar Championship, All Japan Sports Prototype Championship, as well as the 24 Hours of Le Mans from 1990 to 1991.  Designed to combine a mixture of the Fédération Internationale du Sport Automobile (FISA) Group C regulations with the International Motor Sports Association (IMSA) GTP regulations, the 787s were the last Wankel rotary-powered racing cars to compete in the World and Japanese championships, using Mazda's R26B engine.

Johnny Herbert: John Paul "Johnny" Herbert (born 25 June 1964) is a British racing driver.  He raced in Formula One from 1989 to 2000, for 7 different teams, winning three races and placed 4th in the 1995 championship.  He also raced sports cars winning the Le Mans 24 Hours in 1991 driving a Mazda 787B.  He enjoyed much success in lower-level motor racing.

Sailing at the 1924 Summer Olympics – Monotype: The French National Monotype was a sailing event on the Sailing at the 1924 Summer Olympics program in Meulan.  A program of elimination and semi-finals and, where needed, sail-offs were scheduled.  17 sailors from 17 nation competed using eight boats The eight boats were provided by the French Olympic Committee.  A rotation scheme was used to accommodate all 17 sailors.  The sails were swapped so that every sailor used the same sail number every time.  The windvane on top of the mast was in the colors of the sailor's national flag.

Mazda GTP: The Mazda GTP is an IMSA GTP car that was built by Pierre Honegger in 1981.  Based on a Mazda RX-7, the car initially competed in the GTX category as the Mazda RX-7 GTP, before it was rebuilt for the IMSA GTP category in 1983.  Throughout its career, the car used a Mazda 13B Wankel rotary engine, similar to that used in the production RX-7s.  Although the rotary-engined sports prototypes generally had a reputation of being very reliable, the Mazda GTP frequently failed to finish races, and was never able to better the eighth place achieved at the 1983 24 Hours of Daytona.  In 1986, one car was purchased by Erie Scientific Racing, and rebuilt to become the Badger BB.  This car was no more successful or reliable than its predecessor, and was last used in 1989, by which point it was owned by Jack Engelhardt.  The other car, meanwhile, was rebuilt by Honegger into the Denali Speedcar, which was used with moderate success in 1986 and 1987.

Changan Mazda: Changan Mazda (officially Changan Mazda Automobile Co., Ltd.) is an automotive manufacturing company headquartered in Nanjing, China and a 50:50 joint venture between Changan Automobile and Mazda.  The company's principal activity is the manufacture of Mazda brand passenger cars for the Chinese market.  The company was formed in December 2012 after the decision to restructure Changan Ford Mazda, whereby Ford and Mazda agreed to work with Changan as separate joint ventures.

LG Mobile World Cup: The LG Mobile World Cup was an international competition held on January 14, 2010 by LG Electronics in which participants competed using their texting speed and accuracy.  It was held at Gotham Hall in New York City.  Thirteen teams representing their countries competed for a total of $130,000 USD in prize money.

Stewart SF3: The Stewart SF3 was the Formula One car the Stewart Grand Prix team used to compete in the 1999 Formula One season.  It was driven by Rubens Barrichello, in his third season with the team, and Johnny Herbert, who joined from Sauber.

1999 European Grand Prix: The 1999 European Grand Prix (formally the XLIII Warsteiner Grand Prix d'Europe) was a Formula One motor race held on 26 September 1999 at the Nürburgring in Nürburg, Germany.  It was the fourteenth race of the 1999 Formula One season.  The 66-lap race was won by Johnny Herbert driving for the Stewart team.  Jarno Trulli finished second for the Prost team with Rubens Barrichello third in the other Stewart car.

Supporting paragraphs: Stewart SF3 Johnny Herbert
Answer: motor racing