Question

1.

Krishna dai bought 40 bulbs for Rs. 800. 10 of them were broken.
He sold all remaining bulbs at Rs. 30 each. Find his profit or loss
percent​

Answer 1

Profit %= 50%

Explanation:

Price for 40 bulbs: Rs.800

Price for 1 bulb each: 800/40= Rs 20

Price for 10 bulbs= 10*20=Rs. 200

This means that Rs. 200 were wasted due to 10 bulbs being broken.

The remaining bulbs; 30 are sold at a price of Rs 30 each.....

In reality, the price of the remaining 30 bulbs: 30*20=600

Since the 30 bulbs are sold at the price of 30, they altogether cost 30*30=900

Profit= SP-CP; Profit= 900- 600= Rs 300

Profit%= 300*100/600= 50%

Answer 2

He loses 100 Rs. during the process of buying and selling.

Explanation:

1. When he bought 40 bulbs for 800 it meant that every bulb is 20 Rs. worth.

2. 10 of them were broken which means its -200 Rs. from the 800 he spent which leads to him losing 200 Rs.

3. He sold the remaining for 30 Rs. each and he had 30, which means 30 x 30 = 900 Rs.

4. We see that he got 100 more Rs. from the original price he bought the 40 bulbs for but 10 bulbs were lost throughout the way.

( Now there are 2 scenarios in this case )

1. The 10 remaining bulbs were to be lost as in the part of the profit he gained from selling the light bulbs for 30 Rs. which would lead to him losing 200 Rs. because he couldve sold the 10 if they werent broken.

2. The 10 remaining bulbs were to be lost as in part of the original price he bought them for which was 20 Rs. per light bulb which means that if they werent broken he couldve sold them for 100 Rs. .

( Now you may ask me why isnt it 300 Rs. in the first scenario and 200 Rs. in the second its because he gained 100 Rs. in the process of selling the light bulbs that werent broken. So we add 100 Rs. in both scenarios/cases )

I chose the second scenario because it seemed very reasonable to me, but you do as you see preferable.

I hope this helped have a good day!