Answer:
Cost of the pen = Rs.100
Step-by-step explanation:
Let the marked price = x
When the shopkeeper is selling for x, his gain = Rs. 20
Cost price = Marked price - Gain = x - 20 --------(I)
After discount:
Discount = 10%
Marked price after discount = (100 - 10)% of x = 90% of x
= 0.9 * x = 0.9x
When the shopkeeper is selling for 0.9x, his gain = Rs.8
Cost price = Marked price - gain = 0.9x - 8 -------(II)
From (I) and (II)
x - 20 = 0.9x - 8
x = 0.9x - 8 + 20
x = 0.9x + 12
x - 0.9x = 12
0.1x = 12
x = 12/0.1
x = 120
Marked price of pen = Rs.120
Cost price = 120 - 20
Cost price = Rs. 100
Multiply 2 by 1/2 to get 1.
Multiply 1 by 2/3 to get 2/3.
Multiply 2/3 by 3/4 to get 6/12 = 1/2.
Multiply 1/2 by 4/5 to get 4/10 = 2/5.
Multiply 2/5 by 5/6 to get 10/30 = 1/3.
Multiply 1/3 by 6/7 to get 6/21 = 2/7. (I suspect there's a typo in the question.)
And so on, so that the <em>n</em>th term in the sequence is multiplied by <em>n</em>/(<em>n</em> + 1) to get the (<em>n</em> + 1)th term.
Recursively, the sequence is given by

We can solve this exactly by iterating:

and so on down to

or

and with lots of cancellation, we end up with

Answer:
Step-by-step explanation:
26 - 14 = 12
12 ÷ 4 = 3
26 - 3 = 23
23 - 3 = 20
20 - 3 = 17
14, 17, 20, 23, 26
Answer: The three missing arithmetic means in this sequence are 17, 20, 23.
Answer:
roubd it to 20 and you will get 679.90