SSC JE Civil Engineering 30-Oct-2020 Shift 1 Paper

The logic follows here is :
Cube of first number + cube of (first number - 1) = Second number
For $7:559=$ $73+{\left(7-1\right)}^3$ $=7^3+6^3$ $=343+216=559$
1) $11:786$ $={\left(11\right)}^3+{\left(11-1\right)}^3$ $={\left(11\right)}^3+{\left(10\right)}^3$ $=1331+1000$ $=2331\ne 786$
2) $9:593$ $=9^3+{\left(9-1\right)}^3$ $=9^3+8^3$ $=729+512$ $=1241\ne 593$
3) $3:35$ $=3^3+{\left(3-1\right)}^3$ $=3^3+2^3$ $=27+8=35$
4) $5:89$ $=5^3+{\left(5-1\right)}^3$ $=5^3+4^3$ $=125+64$ $=189\ne 89$
Hence, "3 : 35" is the correct answer.