[tex] \bf \: no. \: of \: \: notebook \: is \: = \frac{amount}{cost} \\ \\ \: \: \: \: = \: \frac{124}{15.50} \\ \bf{ \color{blue}{take \: 0 \: for \: multiple} } \\ \\ = \frac{12400}{1550} \\ \\ = 8 \\ \\ \\ [/tex]

[tex] \bf \: so \: notebooks \: = 8[/tex]

hope its help u

[tex]\large \underline \bold{answer}[/tex]:-

Cost of one notebook = 15.50 Rs

means ,

number of books that could be bought in 15.50 Rs = 1 notebook

so , no. of books that could be bought in 1 Rs = (1/15.50) notebook

so , no. of books that could be bought in 124 Rs

➨ (1/15.50) × 124

➨[tex]\rm{\: \dfrac{1}{(\dfrac{31}{2})}\times 124}[/tex]

➨[tex]\rm{\: \dfrac{2}{\cancel{31}}\times \cancel{124} \: \: 4}[/tex]

➨[tex]\rm{\: \: \: \: 2\times 4}[/tex]

➨[tex]\rm{\: \: \: \: \: 8 \: \: notebooks}[/tex]