A manufacturer has 600 L of a 12% solution of acid. How many litres of a 30% acid solution must be added to it so that the acid content in the resulting mixture will be more than 15% but less than 18%?

a polygon has 44 diagonals.find the no. of its sides.

how to solve modulus (2x - 1/x - 1)>2?

an object dropped from cliff falls with a constant acceleration of 10m/s2 find its speed after 2s after it was dropprd

if ²²P_r+1^:20p_r+2 = 11:52 find r

1) find all pairs of consecutive odd positive integers,both of which are smaller than 18,such that their sum is more than 20.

in this why you took x+ 2 not only x please tell me

a scooter covers 20km/h at a uniform speed of 30km/h what should be its speed for the next 40 km if the average speed is 60km/h

if log_0.3(x-1) < log_0.09(x-1), then x lies in the interval....

Find all pairs of consecutive even positive integers, both of which are larger than 5 such that their sum is less than 23.

if ^n-1c_r:ⁿc_r:ⁿ⁺¹c_r=6:9:13 find n and r

1. Solve the following system of inequalities graphically

2x +y ≤ 24 ,

x +y ≤ 11 ,

2x + 5y ≤ 40 ,

x ≥0 , y ≥ 0 

an object moves along a straight line with an acceleration of 2m/s2 if its initial speed is 10m/s what will be its speed 5s later

if all permutations of the letters of the word INDIA are arranged as in a dictionary what is the 60^th word?

A plumber can be paid under 2 schemes as given below:-

I : $600 and $ 50 per hour.

II: $ 170 per hour .

If the job takes n hours, what values of n does Scheme I give the plumber better wages?

in how many ways can the letters of the word FRACTION be arranged so that no two vowels are together.

While drilling a hole in the earth, it was found that the temperature (TC) at x km below the surface of the earth was given by

T = 30 + 25(x - 3), when 3 ≤ x ≤ 15.

Between which depths will the temperature be between 200C and 300C?

 Q. Solve graphically:- 3y-2x<4, x+3y>3, x+y<equals 5.

a milk of 80% conc. is diluted at home by the seller by adding some water to it so that milk conc. is reduced btw 65% to 70% . if 640 l of milk of 80% conc. is available how much water has been added??

 What is the sign scheme method.Can you explain it briefly?

if the products of the roots of the equation x²-3kx+2e^2logk-1=0 is 7, then the roots are real for k=..........

The longest side of a triangle is 3 times the shortest side and the third side

A man wants to cut three lengths from a single piece of board of length 91 cm. The second length is to be 3 cm longer than the shortest and the third length is to be twice as long as the shortest. What are the possible lengths of the shortest board if the third piece is to be at least 5 cm longer than the second?

[Hint: If x is the length of the shortest board, then x, (x + 3) and 2x are the lengths of the second and third piece, respectively. Thus, x = (x + 3) + 2x ≤ 91 and 2x ≥ (x + 3) + 5]

1. First quadrant

2.That half of xy plane which lies above the line 2x+y+6=0

How many litres of water will have to be added to 1125 litres of the 45% solution of acid so that the resulting mixture will contain more than 25% but less than 30% acid content?

in the first four paper each of 100 marks, rishi got 95,72,73,83 marks. if he wants an average of greater than or equal to75 marks and less than 80 marks , find the range of marks he should score in the fifth paper.

 sir i dont understand this line ......

however when both inequalities are multiplied opr divided by a negative number then the sign of the inequality is reserved .. ????

IQ of a person is given by the formula

IQ = (MA/CA)*100,

where MA is the mental age & CA is the chronological age. If 80≤IQ≤140 for a group of 12 yr children, find the range of their mental age.

 what is wavy curve method?

A company manufactures cassettes. Its cost and revenue functions are C(x)=26000+30xand R(x)=43x, respectively, where x is the number of cassettes produced and sold in a week. How many cassettes must be sold by the company to realise some profit?

exactly do we use open and closed brackets...??

The longest side of a triangle is 3 times the shortest side and the third side is 2 cm shorter than the longest side. If the perimeter of the triangle is at least 61 cm, find the minimum length of the shortest side.

5x/ 2+ 3x / 4 39/4. solve the linear inequality..!!

 A point moves such that the sum of its distances from the point (ae,0) and (-ae,0) is 2a. Show that the locus of this point is x²/a² + y²/a²(1-e²) = 1

solve the system of inequalities x+2y>= 20 and 3x+y<=15

Solve:

2x/ 2x²+5x+2 > 1/x+1

15x less than 73, where (i)x belongs to N and (ii) Z.

solve the inequation and represent the solution set on the number line.

A company manufactures cassettes and its cost equation for a week is ( C = 300 + 1.5 x ), while its revenue equation is (R= 2x ) , where x is the number of cassettes sold. How many cassettes must be sold by the company to get some profit?

2x -3 / 3x -7 0. solve this inequality..!!

solve the polynomial inequality

(1) x⁴ - 5x² + 4 < 0

(2) x⁴- 2x² - 63 < or = 0

show graphically that the solution set of the following system of inequalities is empty

x-2y greater than = 0, 2x-y less than = -2 ,x greater than = 0, y greater than = 0

A milk of 80% concentration is diluted at home by the seller by adding some water to it so that milk concentration is reduced between 65% to 70%. If 640 litres of milk of 80% concentration is available, how much water has been added? Which value system the seller is lacking.

IF 1/8! + 1/9! = x/10! . Then find the value of x .

Hi

Solve the equation for x and y: (x - iy) (2 + 3i) = x+2i / 1-i

Solve the following inequations in R.

1. 1/x-1≤2

2. 5x+8/4-x<2

3. x/x-5>1/2

4. 0<-x/2<3

5. |3x-4/2|≤5/12

6. |x-2|/x-2>0

7. |x+2|-x/x<2

8. |2x-1/x-1|>2

9. |x-1|+|x-2|+|x-3|≥6

10. The marks scored by rohit in two tests were 65 and 70. Find the minimum marks he should score in third test to have an average of at least 65 marks.

11. The longest side of a triangle is three times the shortest side and the third side is 2 cm shorter than the longest side if the perimeter of the triangle at least 61cm, find the minimum length of the shortest-side.

12. How many litres of water will have to be added to 1125 litres of the 45% solution of acid so that the resulting mixture will contain more than 25% but less than 30% acid content?

13. A solution of 8% boric acid is to be diluted by adding a 2% boric acid solution to it. The resulting mixture is to be more than 4% but less than 6% boric acid. If there are 640 litres of the 8% solution, how many litres of 2% solution will have to be added?

14. The water acidity in a pool is considered normal when he average pH reading of three daily measurements is between 7.2 and 7.8. If the first two pH reading are 7.48 and 7.85, find the range of pH value for the third reading that will result in the acidity level being normal.

15. Show that the solution set of the following linear inequations is empty set:

15.1) x-2y ≥0, 2x-y ≤-2,x ≥0, y ≥0

15.2) x+2y≤3, 3x+4y ≥12, y ≥1, x ≥0, y ≥0

 If a+b=1, then prove that, (a+1/a)²+(b+1/b)² >25/2      [ where a is not equal to b]

Write the number of integral solutions of x+2/x²+1 1/2.

if x sin³Q +y cos³Q =cosQ.sinQ and x sinQ-y cosQ=0 prove that x²+y²=1

How can we understand which region we have to shade? answer meas soon as possible.