Two articles are sold for the same price such that a profit of 15% is made on one and a loss of 15% is made on the other. Find the gain or the loss per cent on the whole.
For the first article,
Given, profit %=15%
Profit %=SP−CP1CP1×100=15%
⇒SP−CP1CP1=0.15
⇒SP−CP1=0.15×CP1
⇒SP−CP1=0.15CP1+CP1
⇒ SP=1.15×CP1
⇒ CP1=100115×SP ... (1)
For the second article,
Given, loss %=15%
Loss %=CP2−SPCP2×100=15%
⇒CP2−SPCP2=0.15
⇒CP2−SP=0.15×CP2
⇒CP2−0.15×CP2=SP
⇒0.85×CP2=SP
⇒CP2=10085×SP ... (2)
and SP=85100×CP2
=0.85×CP2
From equations (1) and (2),
⇒1.15×CP1=0.85×CP2
⇒CP1=0.851.15×CP2
⇒CP1=1723×CP2
∴ Total CP=CP1+CP2
=1723×CP2+CP2
=4023×CP2
and Total SP=2×SP of each article
=2×(0.85×CP2)=1710×CP2
And Total Loss %=TotalCP−TotalSPTotalCP
=4023×CP2−1710×CP24023×CP2×100
=92304023×100
=2.25%