question number 17 ,18 ,19 and 20 do in copy please with proper solution
Answers
Step-by-step explanation:
17)
The sides are=a,2a+3,3a-3
Perimeter=60cm
a+2a+3+3a-3=60
6a=60
a=10cm
2a+3=2(10)+3
23cm
3a-3=3(10)-3
27 cm
Smallest side is 10cm=a
18)
Given
Number of prizes=100
Total amount=20000 rupees
Each person's prize amount = 100 or 500
Let the number of prizes for 100 rupees be x
Number of prizes for 500 rupees=100-x
100x+500(100-x)=20000
100x+50000-500x=20000
50000-400x=20000
50000-20000=400x
30000=400x
30000/400=x
x=75
100-x=100-75=25
Number of prize for 100 rupees=75 and for 500 rupees=200
19)
Given,
Difference of ages between father and son=24 years
Let sons age be x
Father's age=x+24
5 years ago son's age was 1/3rd of father's age
1(x-5)=(x-24)-5
3
x-5=(x-24-5)3
x-5=(x-29)3
x-5=3x-87
x-3x=-87+5
-2x=-82
x=41
Father's age=41+21
=62 years
Son's age=x=41 years
20)
Ramesh is thrice as old as Naresh
Let Naresh's age=x
Ramesh's age =3x
After 5 years,He will be twice as old as Naresh
3x+5=2(x+5)
3x+5=2x+10
3x-2x=10-5
x=5 years
3x=3(5)
15 years
Rajesh:s age=15 years and Naresh's age=5 years.