NCTB Class 8 Math Chapter Six Exercise 6.2 Solutions by Math Expert. Bangladesh Board Class 8 Math Solution Chapter Six Simple Simultaneous Equations Exercise 6.2 Solution.
|Simple Simultaneous Equations|
10> If the sum and the difference of the two number are 100 and 20 respectively, find the two number:
11> If the sum of the two number is 160 and one number is thrice than other, find the two number:
12> Of two numbers the sum of thrice of the first and double of the second is 59. Again, the difference of the second number from double of the first is 9. Find the two numbers.
13> 5 years ago the ratio of the ages of father and son was 3:1 and after 15 years that will be 2: 1. Find the present age of father and son
Ans: 5 yrs ago, age of father : son = 3:1
15 yrs after, their age = 2:1
1 unit = 20yrs
3 unit = 60 yrs
Therefore, fathers age (60+5) yrs
Son age = (20+5) yrs = 25 yrs
14>? If 5 is added to the numerator of a fraction, it will be 2 Again, if 1 is subtracted from the denominator, it will be 1 Find the fraction
Ans: Let the fraction = x/y
Therefore, x+5 =2
Y – 1 = 1
X+5/y-1 = 2/1
Or, 2y-2 = x+5
Or, x+5 = 2y -2
Or, x = 2y – 5
Or, x = 2y – 7
15> If the sum and the difference of the numerator and the denominator of a proper fraction are 14 and 8 respectively, find the fraction.
16> If the sum and the difference of two digits of a two digit number are 10 and 4 respectively, find the number.
17> The length of a rectangle is 25 metre more than the breadth. If the perimeter of the rectangle is 150 metre, find the length and the breadth of the rectangle.
18> A boy bought 15 notebooks and 10 pencils at Tk. 300. Again, another boy bought same type of 10 note-books and 15 pencils at Tk. 250. Find the price of each notebook and each pencil.
19> A person has Tk. 5,000. He divides that amount between two persons in such a way that the first person’s share is 4 times than the second one. Again, if the first person gives Tk 1,500 to the second person, both the amounts become equal. Find the amount of each person.
20> Solve with the help of graph:
21> If 11 is added to the numerator of a fraction, the value of the fraction becomes 2. Again, if 2 is subtracted from that fraction, the value of the fraction becomes 1.
(A) Form the system of equation considering the fraction (x/y)
(B) Find out the value of (x,y) by the method of elimination.
23> 7x-3y = 31 and 9x-5y=41 are two equations.
(A) Which equation is satisfied by the co-ordinate (4,-1).
(B) Find out (x, y) by elimination method.