Question

A man sold two watches for Rs 6,000 each . On one watch he gains 20% and on the other he loses 20%. What is his net gain or loss per cent ?

give ans step-by-step. Please​

Answer 1

Step-by-step explanation:

Selling price (SP) of each watch = Rs.6000

For 1st watch:-

• SP = Rs.6000

• Gain = 20%

\rm \dashrightarrow CP = \dfrac{100}{100+Gain\%}\times SP⇢CP=100+Gain%100×SP

\rm \dashrightarrow CP = \dfrac{100}{100+20}\times 6000⇢CP=100+20100×6000

\rm \dashrightarrow CP = \dfrac{100}{120}\times 6000⇢CP=120100×6000

\rm \dashrightarrow CP = 5000⇢CP=5000

∴ Cost price of first watch = Rs.5000

For 2nd watch:-

• SP = Rs.6000

• Loss = 20%

\rm \dashrightarrow CP = \dfrac{100}{100-Loss\%}\times SP⇢CP=100−Loss%100×SP

\rm \dashrightarrow CP = \dfrac{100}{100-20}\times 6000⇢CP=100−20100×6000

\rm \dashrightarrow CP = \dfrac{100}{80}\times 6000⇢CP=80100×6000

\rm \dashrightarrow CP = 7500⇢CP=7500

∴ Cost price of second watch = Rs.7500

Total CP of two watches = 7500 + 5000 = Rs.12500

Total SP of two watches = 6000 + 6000 = Rs.12000

Here, CP > SP , so Loss

⇢ Loss = CP - SP

⇢ Loss = 12500 - 12000

⇢ Loss = 500

Now:-

\rm \dashrightarrow Loss\% = \dfrac{Loss}{CP}\times 100⇢Loss%=CPLoss×100

\rm \dashrightarrow Loss\% = \dfrac{500}{12500}\times 100⇢Loss%=12500500×100

\rm \dashrightarrow Loss\% = 4\%⇢Loss%=4%

∴ Net Loss% = 4%