NCERT Solutions are an invaluable aid to students when they need help with their homework, while preparing for exams and while learning. NCERT Solutions are prepared by experts to provide accurate and easy solutions for all questions covered in class 8.
CBSE NCERT Solutions for Class 8 Maths Chapter 2:
The ages of Rahul and Haro on are in the ratio 5:7. Four years later the sum of their ages will be 56 years. What are their present ages?
Let the present ages of Rahul and Haroon be5x years and 7x years respectively. According to
condition, (5x + 4+)+(7x + 4) = 56
( 12 x + 8 )= 56 => 12 x + 8 - 8 = 56 – 8 [Subtracting 8 from both sides]
12x = 48 => 12x/12=48/12 [Dividing both sides by12]
X = 4
Hence, present age of Rahul =5 x 4=20 years and present age of Haroon = 7 x 4=28
The number of boys and girls in a class are in theratio7:5.The number of boys is 8more than the number of girls. What is the total class strength?
Let the number of girls be x.
Then, the number of boys = x+8
According to the question, x+8/x=7/5
5x-7x= -40 [Transposing7x to L.H.S. and 40 to R.H.S.]
−2x = -40 => -2x/-2= -40/-2 [Dividing both sides by 2 ]
x = 20
Hence the number of girls =20 and number of boys = 20+ 8 = 28.
Total class strength =48 students
Baichung’s father is 26 years younger than Baichung’s grandfather and 29 years older than Baichung. The sum of the ages of all the three is 135 years. What is the age of each one of them?
Let Baichung’s age be x years, then Baichung’s father’s age= x 29) years and Baichung’s granddaughter’s age= x + 29 + 26= ( x + 55) years.
According to condition, x + x + 29 + x + 55 = 135
3x + 84 = 135 => 3 x + 84 + 84 = 135 – 84 [Subtracting 84 from both sides]
3x = 51 => 3x/3=51/3[Dividing both sides by3]
X = 17
Hence, Baichung’s age =17years, Baichung’s father’s age = 17+ 29 =46 years and Baichung’s granddaughter’s age =17+29 + 26 = 72 years.