Which expression shows that the sum of any three consecutive whole numbers is a multiple of ?
Answer and explanation
Correct answer: C.
- Step 1: Let the middle number be , so the three numbers are , and .
- Step 2: Add them: .
- Step 3: Since has a factor of , the sum is always a multiple of .
Answer
.
Why not the others: : This adds correctly to , not , so it is an arithmetic slip. : These are not consecutive numbers; they are multiples of . : This multiplies the numbers instead of adding them.
Practise more Algebra.
Free questions with an explanation for every one, and full timed GCSE English and Maths Resits (Grade 4) mock tests.