Question

1- Frame the equations and solve:

a) Raju is four years younger than Biju. Sum of their ages is 28.Find their ages.

b) Raj has 75 more stamps than Mani. The total number of stamps is 325.Find the number of stamps Mani has?

c) The number of marbles Rohan has is 2 more than twice the number of marbles Mohan has. The number of marbles is 140.Find the number of marbles Rohan has d) Rahul is three times as old as s son’s age and the sum of their age is 60.What is Rahul’s age?

Answer 1

a.
       let the age of Raju be x
 therefore, the age of Biju = x + 4

the sum of their ages = x  +( x+ 4) = 28

                                    = 2x= 24
                                    => x = 12

therefore ,  raju's age is 12 and biju's age is x + 4 = 16




b.
     No. of stamp mani has = x
      no. of stamps raj has = x +75

total sum of stamps = 325 = 2x + 75
                                  = 2x = 250
                                   = x = 125
therefore mani has 125 stamps


c.
    Mohan = x
     Rohan = 2x + 2
total no. of marbles = 140

140 = x + (2x+ 2)
138 = 3x
x = 46

therefore rahul has 94 mables



d.
  sons age = x
  Rahul's age = 3x
   3x + x = 60 
    x = 15 

therefore Rahul's age is 3 . 15 = 45

Answer 2

For 1st
Let the age of Biju be x
then, age of Raju = x-4
so, x+x-4=28(sum of ages is 28)
2x=28-4
2x=24
x=12
Biju age =12years
Raju=8years


2nd.

Let the no. os stamps with Mahi be x
then, Raj will have x+75
so,x+x+75=325
2x=325-75
2x=250
x=125
Mahi has 125stamps
Raj has 125+75=200stamps


3rd.
Let the no.of marbles Mohan has be x
then, Rohan has 2x+2
x+2x+2=140
3x=140-2
3x=138
x=46
Mohan has 46 marbles.


4rth.
Let the age of son be x
Rahul age=3x
x+3x=60
4x=60
x=15
Son age is 15 years
Rahul age 3×15=45 years