Word Problem - Whole Number

Question :

At first Ali has 20 marbles more than John. After John give Ali 5 marbles, then Ali has 3 times as many marble as John. How many marbles do Ali & John has at first ?

Model Method

2 units   5 + 20 + 5 = 30

1 unit15

At first Ali has 3 x 15 -5 = 40 marbles

and John has 15 + 5 = 20 marbles

                                          ANS :  Ali has 40 marbles John has 20 marbles