Mrs. thapa bought 150 kg of oranges.18 kg of oranges were rotten and not fit for selling. If she sold the remaining quantity of oranges at the rate of Rs 80 per kg and gained 10%. Find the rate of cost price of oranges. Help!!

Rs.64

Step-by-step explanation:

Amount of oranges:

Oranges sold:

Money made:

Selling price of 150 kg:

Cost price:

Rs64.00/kg  

Step-by-step explanation:

1. Calculate the amount of good oranges

Total amount of oranges    = 150 kg

Amount of rotten oranges =    18 kg

Amount of good oranges    = 132 kg

2. Calculate the income from  the good oranges

3. Calculate the net unit rate of income

The income from the good oranges was Rs10 560.

Based on 150 kg of oranges, the unit rate of income was

4. Calculate the original unit rate of cost

Let x = original unit cost. Then

0.10x = 10 % of original unit cost and

1.10x = 10 % over original unit cost

1.10x = RS70.40/kg

        x = (RS70.40/kg)/1.10 = Rs64.00/kg

The original unit rate of cost was Rs64.00/kg.