Question

Sapna bought two books for Rs.800 each. She sold one book at a loss of 10% and other at a profit of

15%. Find the selling price of each and also find the total profit or loss​

Answer 1

$\huge \underline {\sf{given}}$

• CP of two books = Rs. 800 each.
• 1st book was sold at a loss of 10 %
• 2nd book was sold at a gain of 15%

$\huge \underline { \sf{to \: find}}$

• SP of both book
• total profit or loss

$\huge \underline {\sf{solution}}$

$\rm{CP \: of \: 1st \: book = rs.800}$

$\rm{loss\% = 10\%}$

$\sf{SP \: of \: 1st \: book} = \frac{(100 - loss \: \% )}{100} \times CP$

$\sf = \frac{100 - 10}{100} \times 800 \\ \\ = \sf{ \frac{90}{100} \times 800 = rs.720}$

$\rm{CP \: of \: 2nd \: book} = \: rs. \: 800 \\ \rm{gain\% = 15\%}$

$\sf{SP \: of \: 2nd \: book} = \frac{100 + gain\%}{100} \times CP \:$

$= \rm{rs.( \frac{100 + 15}{100} \times 800})$

$\rm{rs.( \frac{115}{100} \times 800}) \: \\ \\ = \: \sf{rs.920}$

$\sf{total \: CP \: of \: 2 \: books = \: rs. \: (800 \times 2) } \\ \rm{= rs.1600 \: }$

$\sf{ \: total \: SP \: of \: 2 \: books = rs.(920 + 800)} \\ = \rm{rs. \: 1720}$

$\rm{since \: (SP) > (CP)} \\ \sf{ \: there \: is \: gain \: in \: the \: whole \: transaction}$

$\rm{gain = rs.(1720 - 800)} \\ \rm{= rs . \: 920}$

$\sf({gain \: \% = \frac{gain}{total \: CP \: } \times 100)}\%$

$= \rm({ \frac{920}{800} \times 100}) \\ \\ = \rm{(115)\%} \\ \\ = \frac{115}{100} \\ \\ = 1.15\%$

Answer 2

PROFIT% = 0.25%

Step-by-step explanation:

1st BOOK:-

C.P= 800

P%=15%

UNITARY:-

800 100

x 115

S.P=800×115/100

S.P=920

PROFIT=SP-CP

P=920-800

P=120

2nd BOOK:-

CP=800

L%=10%

UNITARY

800 100

x 90

S.P=800×90/100

S.P=720

LOSS=CP-SP

LOSS=800-720

LOSS=80

TOTAL PROFIT :-

PROFIT=120

LOSS=(-80) [IT IS NEGATIVE BECAUSE IT IS A LOSS]

TOTAL PROFIT OR LOSS= 120 - 80

TOTAL PROFIT= 40

TOTAL P%:-

TOTAL CP= 800+800

TOTAL CP=1600 [BOTH BOOKS]

P%=P/CP × 100

THEREFORE,

P%= 40/1600 × 100

P%= 1/4% OR 0.25%