Select the option that is related to the third number in the same way as the second number is related to the first number.
130 : 222 :: 350 : ?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 520
Numbers such as 130, 222 and 350 lie just above the cubes 125, 216 and 343, so each is written as a cube plus a small number.
\(130=125+5=5^3+5\)
\(222=216+6=6^3+6\)
So the pair goes from \(n^3+n\) to the same form for the next number, \(n=5\) to \(n=6\)
\(350=343+7=7^3+7\), so here \(n=7\)
The next number is 8: \(8^3+8=512+8=520\)
So the missing number is 520.