Question

a shop keeper brought locks at 34rs a dozen andsold them at dozen locks for 52rs.the number of locks he should sell to gain rs 900is.​

Answer 1

Given :

Cost price of 1 Dozen = Rs. 34.

Selling price of 1 Dozen = Rs. 52.

Total profit = Rs. 900.

According to the question :

☆ 1 dozen = 12 locks.

☞ CP of 12 locks = Rs. 34

CP of 1 lock = 34 / 12

=> Rs. 2.8

☞ SP of 12 locks = Rs. 52

SP of 1 lock = 52 / 12

=> Rs. 4.3

☆ SP > CP , So, it's a Profit.

☞ Profit = SP - CP

=> 4.3 - 2.8

=> Rs. 1.5

☞ No. of. locks should be sold = Total profit / Profit of 1 lock

=> 900 / 1.5

=> Rs. 600.

• So, he should sell 600 locks for Rs. 900.

Answer 2

${ \bf{ \underline{ \red{ \underline{ \red{Question}}}} : - }}$

A shop keeper brought locks at Rs 34 a dozen and sold them at dozen locks for Rs 52 . The number of locks he should sell to gain Rs 900 .

${ \bf{ \underline{ \red{ \underline{ \red{Given}}}} : - }}$

• A shop keeper brought locks at Rs 34 a dozen and sold them at dozen locks for Rs 52.

${ \bf{ \underline{ \red{ \underline{ \red{Find}}}} : - }}$

• The number of locks he should sell to gain Rs 900 .

${ \bf{ \underline{ \red{ \underline{ \red{Solution}}}} : - }}$

We know that 1 dozen mean's 12 item's.

{ According to given }

cost price & selling price of 12 lock

{ 1 dozen lock's } are given below :-

• Cost Price ( C.P ) = Rs 34
• Selling Price ( S.P ) = Rs 52

To find C.P & S.P of one lock

${ \sf{ \purple{C.P \: of \: one \: lock = }} \: { \frac{C.P \: of \: 12 \: lock }{12 } }} \\ \\ { \sf{ \purple{C.P \: of \: one \: lock = }} \: { \frac{34}{12 } }} \\ \\ { \sf{ \purple{C.P \: of \: one \: lock = }} \:Rs \: 2.83 } { \sf{ \red{ \: (approx)}}}$

${ \sf{ \purple{S.P \: of \: one \: lock = }} \: { \frac{S.P \: of \: 12 \: lock }{12 } }} \\ \\ { \sf{ \purple{S.P \: of \: one \: lock = }} \: { \frac{52}{12 } }} \\ \\ { \sf{ \purple{S.P \: of \: one \: lock = }} \: Rs\: 4.33 } { \sf{ \red{ \: (approx)}}}$

• Profit = S.P - C.P

${ \sf{ \dashrightarrow{ \red{Profit \: = }} \: 4.33 \: - \: 2.83}} \\ \\ { \sf{ \dashrightarrow{ \red{Profit \: = }} \:Rs \: 1.5}}$

To find number of lock to gain

Rs 900

${ \sf{ \blue{Number \: of \: lock's }} \: = \: {\frac{Total\: profit}{Profit\: on \: one\: lock}}} \\ \\ { \sf{ \blue{Number \: of \: lock's }} \: = \: { \cancel{\frac{ 900}{1.5}}}} \\ \\ { \sf{ \blue{Number \: of \: lock's }} \: = \: 600}$

Hence, he should sell 600 locks to gain Rs 900 .

i hope it helps you.