All the factors are found when the next value is part of a pair that has already been identified. The difference is 3. The 3rd multiple of seven is 7 × 3 = 21. The 4th multiple of six is 6 × 4 = 24.

Scientists don't know exactly what causes the mutations that turn plasma cells cancerous, but certain factors may affect a person's risk. A family history of multiple myeloma and certain plasma ...