Ravipurchases $90$ pens and sells $40$ pens at a gain of $10 \%$ and $50$ pens at a gain of $20 \% .$ Had he sold all of them at a uniform profit of $15 \%$ he would have got $Rs.\, 40$ less. Find the cost price of each pen in $Rs.$
$80$
$75$
$90$
$100$
Nutan bought $30$ dozens of oranges for her juice stall in the school fair. She paid $Rs.\, 8$ per dozen of oranges. She also had to pay $Rs\, 500$ as the stall fee to the school authorities. She calculated that each glass'of juice would need $3$ oranges. How much should she charge per glass of juice so as to make $20 \%$ profit in $Rs?$
Mahesh purchased $25\, kg$ of rice at $32$ per $kg$ and $15\, kg$ of rice at $Rs\,.36$ per $kg.$ He mixed the two varieties of rice and sold it at $Rs.\, 40.20$ per $kg.$ What is the percent profit earned?
A discount dealer professes to sell his goods at cost price but uses a weight of $960\, gms$ instead of a $Kg$ weight. Find his gain $\% ?$
Aditya bought a scooter for a certain sum of Money. He spend $15 \%$ of cost price on repair and sold it for a profit on $Rs.$ $1104.$ What will he spend on repair if profit he got was $20 \%$ in $Rs.?$
Raman, Manan and Kamal are partners and invest in a business such that Raman invests $\frac{2}{5}\,^{th}$ of total and Manan invests $\frac{3}{8}\,^{th}$ of the total. What is the ratio of profits of Raman, Manan and Kamal respectively?