Bangladesh Bank recruitment test math solution for the position of Cash officer 2011. Cash Officer written examination math solution of Bangladesh 2011.

**01.** The area of a rectangular plot is 323 square meters. Its perimeter is 72 meters. Find the length and breadth of the plot.

**Solution:**

Let, length = x and breadth = y.

So, perimeter, 2(x + y) = 72

Or, x + y = 36

Or, x = 36 – y

Again, area, xy = 323

Or, (36 – y)y = 323

Or, 36y – y^2 = 323

Or, y^2 – 36 + 323 = 0

Or, y^2 – 19y – 17y + 323 = 0

Or, y(y – 19) – 17(y – 19) = 0

Or, (y – 19)(y – 17) = 0

If, breadth y = 17 then length x = 323/17 = 19

Again, if, breadth y = 19 then length x = 323/19 = 17

Since breadth must not be more than length so, breadth, y = 17 and length x = 19 Ans.

**02.** Mr. Hasan has few notes of Tk. 10 and Tk. 50. A total of his 150 notes amount to Tk.5100. What is the number of each kind of note?

**Solution:**

Let, the number of 10 taka notes be x

And the number of 50 taka notes be (150 – x)

According to the question,

10x + 50(150 – x) = 5100

Or, 10x + 7500 – 50x = 5100

Or, 40x = 2400

Or, x = 60

The number of 10 Tk. Notes = 60 and the number of 50Tk. notes = 150 – 60 = 90 Ans.

**03.** The length of rectangular plot is greater than its breadth by 20 meters. If the perimeter of the plot is 160 meters, what is the area of the plot in square meters?

**Solution:**

Let, breadth be x meters and length be (x + 20) meters

So, perimeters =2(x + x +2) = (4x + 40) meters.

According to the question,

4x + 40 = 160

Or, 4x = 160 – 40

Or, x = 30

So, breadth = 30 meters and length = 30 + 20 = 50 meters.

Area of the pot = (50 × 30) = 150 sq. meters. Ans.