Let CP of the watch be ₹ N.
Then , According to the question,
[(75 - N)/ N] x 100 = N

Correct Option: C

Let CP of the watch be ₹ N.
Then , According to the question,
[(75 - N)/ N] x 100 = N
⇒ (75 - N) x 100 = N²
⇒ N² + 100N - 7500 = 0
⇒ N² + 150N - 50N - 7500 = 0
⇒ N(N + 150) - 50 (N + 150) = 0
⇒ (N + 150) (N - 50) = 0
⇒ N = ₹ 50

Let each lot of onion-contain N kg onion,
Then total cost price of these two lots together = 10N + 15N = 25N
Selling price of whole lot = 15 x (N + N) = 15 x 2N = 30N

Correct Option: C

Let each lot of onion-contain N kg onion,
Then total cost price of these two lots together = 10N + 15N = 25N
Selling price of whole lot = 15 x (N + N) = 15 x 2N = 30N
Profit percentage = [(30N - 25N)/25N] x 100 %
= (5/25) x 100%
= 20%

SP of 1 lemon = ₹ 14/5
Let CP of 1 lemon = N
According to the question, (N x 140)/100 = 14/5

Correct Option: C

SP of 1 lemon = ₹ 14/5
Let CP of 1 lemon = N
According to the question, (N x 140)/100 = 14/5
∴ N = ₹ 2
∴ CP for 12 lemons = 12 x 2 = 24

Let the cost price be ₹ N.
SP of 1 orange = ₹ 30/32 = ₹ 15/16

According to the question, 75N/100 = 15/16
∴ N = [(15 x 100)/75] x 16 = ₹ 5/4

SP of 1 orange with 20% profit = ₹ [(5/4) x 120]/100 = ₹ 3/2

Correct Option: B

Let the cost price be ₹ N.
SP of 1 orange = ₹ 30/32 = ₹ 15/16

According to the question, 75N/100 = 15/16
∴ N = [(15 x 100)/75] x 16 = ₹ 5/4

SP of 1 orange with 20% profit = ₹ [(5/4) x 120]/100 = ₹ 3/2
∴ In ₹ 3/2, the number of oranges sold = 1
∴ in ₹ 24, the number of oranges sold = (2/3) x 24 = 16

Total cost price = ₹ (120 x 100) = ₹ 12000
Total expenditure = 480 + (1/2) x 120 + 60 = ₹ 600
Total cost price = 12000 + 600 = ₹ 126000
Gain = 40%
SP of 120 reams = 12600 x (140/100)

Correct Option: B

Total cost price = ₹ (120 x 100) = ₹ 12000
Total expenditure = 480 + (1/2) x 120 + 60 = ₹ 600
Total cost price = 12000 + 600 = ₹ 126000
Gain = 40%
SP of 120 reams = 12600 x (140/100) = ₹ 17640
∴ SP per ream = 17640/120 = ₹ 147