Answer to Question #125466 in Algebra for Tozama Koka

Question

Jabu had a few marbles. Today he played and doubled his number of marbles. Then Thabo gave him three marbles for free. Jabu has 21 marbles now. How many did he have before he started playing?
Solve this problem using a suitable model.

Answer 1

Let the number of marbles before juba play the game be X

The number of marbles after playing the game will be 2X

Thabo gift marble to juba = 3

The total marble is equal to 2X + 3

EQUATION

2X + 3 = 21

2X=21-3

2X=18

X=9

Number of marbles before the started to play = x

Answer= 9