In the following question, choose the one option which is similar to the given set.
Given set: (21, 91, 35)
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (21, 51, 15)
In the given set, the middle number is the first number plus twice the third: \(21+2\times35=91\). Test each option with the same rule:
Option (1) (21, 51, 16): \(21+2\times16=53\), not 51
Option (2) (21, 61, 35): \(21+2\times35=91\), not 61
Option (3) (21, 51, 15): \(21+2\times15=51\), which fits
Option (4) (21, 81, 25): \(21+2\times25=71\), not 81