Answer:
given,
selling price (sp)=rs 5 ×30
=rs 150
now, gain %=20%
cost price (cp)=
[tex] \frac{sp \times 100}{100 + gain\%} [/tex]
[tex] = \frac{150 \times 100}{100 + 20} [/tex]
therefore cp= rs125
now,
again in 2nd case
sp= rs 27×5
therefore sp=rs 135
and cp= rs125
now, sp>cp so,
[tex]gain\% = \frac{sp - cp}{cp} \times 100\%[/tex]
or, gain=
[tex] = \frac{135 - 125}{125} \times 100\%[/tex]
therefore gain %= 8%.... is answer
hope it helps..