NCERT Quadratic Equations Word Problems MCQs
CBSE Class 10 Mathematics – Quadratic Equations Word Problems MCQs
Chapter 4: Quadratic Equations
Based on NCERT | As per Latest CBSE Board Examination Pattern
1. The product of two consecutive positive integers is 56. The integers are:
Correct Answer: A
Explanation: Let integers be x and x+1.
x(x+1)=56 ⇒ x²+x−56=0 ⇒ (x−7)(x+8)=0 ⇒ x=7.
Numbers are 7 and 8.
Explanation: Let integers be x and x+1.
x(x+1)=56 ⇒ x²+x−56=0 ⇒ (x−7)(x+8)=0 ⇒ x=7.
Numbers are 7 and 8.
2. The sum of squares of two consecutive numbers is 85. The numbers are:
Correct Answer: A
Explanation: Let numbers be x and x+1.
x²+(x+1)²=85 ⇒ 2x²+2x+1=85 ⇒ x²+x−42=0 ⇒ x=6.
Explanation: Let numbers be x and x+1.
x²+(x+1)²=85 ⇒ 2x²+2x+1=85 ⇒ x²+x−42=0 ⇒ x=6.
3. A number exceeds its reciprocal by 3. The number is:
Correct Answer: B
Explanation: Let number be x.
x − 1/x = 3 ⇒ x² − 1 = 3x ⇒ x² − 3x − 1 = 0 ⇒ x= (3 ± √13)/2.
Positive integer approx is 2.
Explanation: Let number be x.
x − 1/x = 3 ⇒ x² − 1 = 3x ⇒ x² − 3x − 1 = 0 ⇒ x= (3 ± √13)/2.
Positive integer approx is 2.
4. The area of a rectangle is 60 m² and length is 5 m more than breadth. Breadth is:
Correct Answer: B
Explanation: Let breadth = x, length = x+5.
x(x+5)=60 ⇒ x²+5x−60=0 ⇒ (x−6)(x+10)=0 ⇒ x=6.
Explanation: Let breadth = x, length = x+5.
x(x+5)=60 ⇒ x²+5x−60=0 ⇒ (x−6)(x+10)=0 ⇒ x=6.
5. Product of two numbers is 96 and their difference is 4. The numbers are:
Correct Answer: A
Explanation: Let numbers be x and x+4.
x(x+4)=96 ⇒ x²+4x−96=0 ⇒ x=8.
Explanation: Let numbers be x and x+4.
x(x+4)=96 ⇒ x²+4x−96=0 ⇒ x=8.
6. If area of square is 121 cm², its side is:
Correct Answer: C
Explanation: Side² =121 ⇒ side=√121=11.
Explanation: Side² =121 ⇒ side=√121=11.
7. The speed of a boat in still water is 15 km/h. It travels 30 km upstream in 3 hours. Speed of stream is:
Correct Answer: C
Explanation: Upstream speed=30/3=10 km/h.
15−x=10 ⇒ x=5 km/h.
Explanation: Upstream speed=30/3=10 km/h.
15−x=10 ⇒ x=5 km/h.
8. The sum of two numbers is 10 and their product is 21. The numbers are:
Correct Answer: A
Explanation: x+y=10, xy=21 ⇒ x²−10x+21=0 ⇒ (x−3)(x−7)=0.
Explanation: x+y=10, xy=21 ⇒ x²−10x+21=0 ⇒ (x−3)(x−7)=0.
9. The area of rectangular garden is 528 m² and length is 2 m more than breadth. Breadth is:
Correct Answer: B
Explanation: x(x+2)=528 ⇒ x²+2x−528=0 ⇒ x=22.
Explanation: x(x+2)=528 ⇒ x²+2x−528=0 ⇒ x=22.
10. If one root of quadratic equation is 2 and sum is 5, other root is:
Correct Answer: B
Explanation: 2 + x = 5 ⇒ x = 3.
Explanation: 2 + x = 5 ⇒ x = 3.
11. The square of a number exceeds 5 times the number by 6. The number is:
Correct Answer: A
Explanation: x²=5x+6 ⇒ x²−5x−6=0 ⇒ (x−6)(x+1)=0 ⇒ x=6 or −1.
Valid positive is 6.
Explanation: x²=5x+6 ⇒ x²−5x−6=0 ⇒ (x−6)(x+1)=0 ⇒ x=6 or −1.
Valid positive is 6.
12. A train travels 360 km at certain speed. If speed increases by 5 km/h, time reduces by 2 hours. Original speed is:
Correct Answer: A
Explanation: Let speed=x.
360/x − 360/(x+5)=2 ⇒ x=40.
Explanation: Let speed=x.
360/x − 360/(x+5)=2 ⇒ x=40.
13. The product of two consecutive even numbers is 168. The numbers are:
Correct Answer: A
Explanation: Let numbers be x and x+2.
x(x+2)=168 ⇒ x=12.
Explanation: Let numbers be x and x+2.
x(x+2)=168 ⇒ x=12.
14. If area of triangle is 84 cm² and base is 4 cm more than height, height is:
Correct Answer: C
Explanation: (1/2)x(x+4)=84 ⇒ x²+4x−168=0 ⇒ x=12.
Explanation: (1/2)x(x+4)=84 ⇒ x²+4x−168=0 ⇒ x=12.
15. The difference of two numbers is 3 and their product is 54. The numbers are:
Correct Answer: A
Explanation: Let numbers x and x+3.
x(x+3)=54 ⇒ x=6.
Explanation: Let numbers x and x+3.
x(x+3)=54 ⇒ x=6.
16. The square of a positive number is 4 times the number. The number is:
Correct Answer: A
Explanation: x²=4x ⇒ x(x−4)=0 ⇒ x=4.
Explanation: x²=4x ⇒ x(x−4)=0 ⇒ x=4.
17. If perimeter of rectangle is 26 cm and area 40 cm², breadth is:
Correct Answer: A
Explanation: 2(l+b)=26 ⇒ l+b=13, lb=40 ⇒ x²−13x+40=0 ⇒ x=5.
Explanation: 2(l+b)=26 ⇒ l+b=13, lb=40 ⇒ x²−13x+40=0 ⇒ x=5.
18. A number when decreased by 4 gives product 60 with itself. The number is:
Correct Answer: A
Explanation: x(x−4)=60 ⇒ x²−4x−60=0 ⇒ x=10.
Explanation: x(x−4)=60 ⇒ x²−4x−60=0 ⇒ x=10.
19. The area of square is equal to area of rectangle of sides 12 m and 3 m. Side of square is:
Correct Answer: A
Explanation: Area=36 ⇒ side=√36=6.
Explanation: Area=36 ⇒ side=√36=6.
20. The sum of squares of two numbers is 25 and product is 12. The numbers are:
Correct Answer: A
Explanation: x²+y²=25 and xy=12.
(x+y)²=25+24=49 ⇒ x+y=7.
x²−7x+12=0 ⇒ x=3,4.
Explanation: x²+y²=25 and xy=12.
(x+y)²=25+24=49 ⇒ x+y=7.
x²−7x+12=0 ⇒ x=3,4.
