Question

10. A sold a calculator to B at 20% profit. B sold it to C at 5% profit. If C paid 3441 for it, what was the cost price of the calculator. ​

Answer 1

Answer:

2730.95

Step-by-step explanation:

SHORT APPROACH

20% = 20/100 = 1/5

5% = 5/100 = 1/20

A. B. C

5. 6

20. 21

Now fill the vacant position with preceding or succeeding numbers as shown and multiply.

A. B. C

5. 6. 6

20 20. 21

-----------------------

100. 120. 126

126 => 3441

100 => 3441*100/126 ≈ 2730.95

LONG APPROACH

If,

Sp of B = 3441

Cp of B = x

Sp of A = x

Cp of A = y

Then, for B

(3441 - x)/x = 5/100 = 1/20

(3441 - x) × 20 = x

68820 - 20x = x

x = 68820/21

Now, for A

(x-y)/y = 20/100 = 1/5

5x - 5y = y

y = 5x/6 = 5×68820/(21×6) = 2730.95