See the posting on Fatimah and Hairu play Congkak to know about Congkak game.
Lower primary school mathematics question LPQ42
Fatimah started a Congkak game with Hairu. She had an equal number of blue and green marbles when the game started. After the first round of game, she giving away 36 blue marbles to Hairu but gaining another 84 green marbles from him. She found that she had 4 times as many green marbles as blue marbles. How many blue marbles did Fatimah have at first?
3 units = 84 + 36 = 120
1 unit = 40
Number of blue marbles = 40 + 36 = 76