New Learning Composite Mathematics SK Gupta Anubhuti Gangal Class 8 Linear Equations Self Practice 7B Solution
(1) Answer the following.
(a) If x is an integer, what are the next two larger integers?
(b) If x is an even integer, what are the next two larger even integers?
(c) The sum of two integers is -8. If one integer is represented byx, represent the other integer in terms of x.
(d) The difference between a number y and another number is 20. Represent the other number in terms of y.
(e) If Priya is n years old now, how old will she be next year and 5 years from now? How old was she 10 years ago?
(f) Over a period of 4 years, a businessman has tripled his early profit. If his profit was Rs. x at the beginning of this period, what was his at the end of this period?
(g) The tens digit of a number is 4 less than its ones digit. If the ones digit is x, then what is the number?
(h) What is the number if the digits in (g) part are interchanged?
(i) The denominator of a fraction is 3 more than its numerator. If the numerator is y, then what is the fraction?
(j) What is the angle marked a in the figure?
SOLUTION Number 1:
(2) Forty-six more than a number is 13. What is the number?
(3) The sum of three consecutive odd numbers is 33. What are the numbers?
(4) The sum of two numbers is 87. If twice the smaller number is added to the larger number, the result is 120. Find the larger number.
(5) Find three conswecutive numbers such that the sum of the first and second is 15 more than the third.
(6) The sum of three numbers is 57. If twice the first is 6 less than the second and the second numbers is 10 more than the third, find the numbers.
SOLUTION Number 2 to 6:
(7) In a 2 digit number, digit in units place is twice the digit in tens place. If 27 is added to it, digits are recersed. Find the number.
SOLUTION:
(8) If a certain number is added both to the numerator and to the denominator of 9/17, the new graction reduces to 5/7. Find the number.
(9) Find four consecutive odd numbers such that three times the largest number added to twice the smallest number is 93. Which of these are prime numbers?
(10 sum of the digits of a 2 digit number is 11. The given number is less than the number obtained by interchanging the digits by 9. Find the number.
SOLUTION:
(11) In the same innings of a cricket match, four batsman’s scores are consecutive numbers which are divisible by 5. If theeir total contribution to the innings is 70 runs, how many runs, does each batsman score?
(12) The numerator of a rational number is 2 less than the denominator. When is subtracted from both the numerator and denominator, the number’s simplest form is 1/2. What is the rational number?
SOLUTION:
(13) A boy was p years old r years ago. How old is he now? How old will he be in (p – r) years time?
(14) Three years ago, Hari was 5 years older than Anushka. If he is now twice as old as she is, find their present ages.
(15) Ravi is now 6 years older than Neeta. Three years ago, he was twice as old as she was then. Find their present ages.
SOLUTION:
(16) Deepas mother is 4 years more than 3 times as old as Deepa is now, six years from now she will 8 years more than twice as old as Deepa will be then. How old is each of them now?
(17) The present ages of two children are in the ratio 2:3. Five years ago, the ratio of their ages was 1:2. Find their present ages.
SOLUTION:
(18) A playground is 30 m longer than it is wide. If its perimeter is 300 m, what is its area?
(19) In the figure, all the corners are right angled and the dimensions are given in centimetres. Find, a if the perimeter of the shaded area is 1 metre.
SOLUTION:
(20) The figure shows the the lengths in centimetres of the sides of a triangle. If the triangle is equilateral, find the value of x and y. Also find the perimeter of the triangle.
SOLUTION:
(21) Six paving stones are arranged in a square array as shown in the figure. If each stone has a length 20 cm greater than its width, find
(a) the dimension of each stone,
(b) the area of the ground space that the stones are occupying.
(c) the perimeter of the same ground space.
(22) I travel 25 km in 2 and half hours, walking part of the way at 3 km/h and covering on scooter the rest at 24 km/h. How far do I walk?
SOLUTION:
(23) Figure represents a cyclists riding from A to B and back again; the double journey takes 5 hours. Find x.
(24) A man rows upstream in still water at 3 km/h and back to the same at 5 km/h; he takes 48 minutes altogether. How upstream did he go?
SOLUTION:
(25) Distance between two places A and B is 210 km. Two cars start simultaneously from A and B in opposite directions and distance between them after 3 hours is 54 km. If spees of one car is 8 km/h less than that of the other, then find the speed of each.
SOLUTION:
(26) A streamer covers the distance between two parts in 3 hours when it goes downstream and 5 hours when it goes upstream. Find the speed of the streamer upstream if the stream flows at 3 km/h.
(27) Find an angle such that the measure of its supplement is 10 degrees less than 3 times the measure of its complement.
SOLUTION:
(28) The figure shows in degrees the angles at which a line is cut by two parallal lines. Find the value of x.
(29) In the figure, ∠ACB = 4∠ABC, and CP bisects ∠ACB, Find
(a) ∠ABC
(b) ∠BPC
SOLUTION:
(30) An apple has 29 more calories than a pach and 13 fewer calories than a banana. If 3 apples have 43 fewer calories than 2 bananas and 2 peaches, how many calories does an apple have?
SOLUTION:
(31) Rishi’s mother gave him Rs. 245 with which to buy New Year cards. If he got some Rs. 10 cards, 2/3 as many Rs. 5 cards, and 1/5 as many Rs. 15 cards, how many of each kind did he get?
SOLUTION:
(32) One-fifth of an estate is left to a sister, one fourth to a son, one-sixth to a brother and the remainder, which is Rs. 5,75,000 to the widow. What is the value of the estate?
(33) An employee works in a company on a contract of 30 days on the condition that he will receive Rs. 120 for each day he works and he will be fined Rs. 10 for each day he is absent. If he receives Rs. 2300 in all, for how many days did he remain absent?
SOLUTION:
It is very much tough
Not at all
Where is 21
Where is question no. 21
Sir question 19 is wrong as another answer is given in the book
26 question bhi nhi hai
21 no. Nhi h
Sir please also make your YouTube channel for explaining these problems
There is a mistake in ques 29 .