Shyam invested money in the stock market

Given that question: Shyam invested money in the stock market. In the first year, his stock increased 20%. He paid his stock broker $300 and then lost $450. He withdrew $500, and then his remaining investment doubled. Shyam’s investment is now worth $7100. How much was Shyam’s original investment?

The solution is as follows:

Let the amount Shyam invested in the stock market be x, then in the first year his stock increased by 20% giving 1.2x.

He paid his stockbrocker $300 to have 1.2x - $300 left, and he lost $450 to have 1.2x - $300 - $450 = 1.2x - $750 left.

He withdrew $500 to have 1.2x - $750 - $500 = 1.2x - $1,250 left.

His remaining investment doubled to have 2(1.2x - $1,250) = 2.4x - $2,500

Shyam's investment is now worth $7,100 which means that
2.4x - $2,500 = $7,100
2.4x = $7,100 + $2,500 = $9,600
x = $9,600 / 2.4 = $4,000

Therefore, the value of Shyam's original investment is $4,000

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)