1/5 of a class of children signed up for a mathematics competition. There were 10 boys and 30 girls who did not sign up. How man
2 answers:
You might be interested in
Answer: The dimension of the lawn = 85 × 40
Area of the lawn = 3250 square feet
Step-by-step explanation:
Let x represents the width of the rectangle,
Then According to the question,
The length of the rectangle = 2 x + 5
Also it is given that the perimeter of the rectangle = 250 feet.
But we know that the perimeter of the rectangle = 2 × ( length + width)
Thus, the perimeter of the rectangle = 2( 2x+5+x) = 2(3x+5) = 6x+10
If x = 30, the perimeter of the rectangle = 6 × 30 + 10 = 190 < 250
Thus, x ≠ 10.
If x = 50, the perimeter of the rectangle = 6 × 50 + 10 = 310 > 250
Thus, x ≠ 50
If x = 40, the the perimeter of the rectangle = 6 × 40 + 10 = 250 = 250
Thus, x = 40
Therefore, the width of the rectangle, x = 40 feet.
And, the length of the rectangle, 2 x + 5 = 2 × 40 + 5 = 85 feet.
1) The dimension of the rectangle = 85 × 40
2)The area of the rectangle = length × width = 85 × 40 = 3250 square feet.
