Three of the following four number groups are alike in a certain way. Choose the one that does not belong to the group.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (17, 4, 5)
Compare the first number with the product of the other two.
Option (1) (45, 6, 7) — 6 × 7 = 42 and 42 + 3 = 45.
Option (2) (15, 3, 4) — 3 × 4 = 12 and 12 + 3 = 15.
Option (3) (33, 5, 6) — 5 × 6 = 30 and 30 + 3 = 33.
Option (4) (17, 4, 5) — 4 × 5 = 20 and 20 + 3 = 23, not 17.
In three groups the first number is the product of the other two plus 3; (17, 4, 5) breaks this, so it is the odd one out.