BPSC 60th-62nd Prelims Exam 12 Feb 2017 Solved Paper

Given expression in the question,
${\mathit{x}}^3+3\mathit{y}-3$
putting the value of $\mathit{x}=1$
$1^3+3\mathit{y}-3=7$
$\Rightarrow 3\mathit{y}-2=7\Rightarrow \mathit{y}=3$
Again putting the value of $\mathit{x}=2$ in the expression
$2^3+3\mathit{y}-3=20$
$\Rightarrow 3\mathit{y}+5=20\Rightarrow 3\mathit{y}=15\Rightarrow \mathit{y}=5$
similarly when $\mathit{x}=5,\mathit{y}=11$
$\therefore$ Fifth value of expression is
$5^3+3.11-3=125+33-3$
$=125+30=155$