Diana had some marbles at first. She gave 26 of her marbles to her brother and 14 of her marbles to her neighbour. After that, her mother gave her another 7 marbles. She had 42 marbles in the end. How many marbles did Diana have at first?
Fraction of marbles left after giving to her brother and her neighbour
= 1 -
26 -
14 = 1 -
412 -
312 = 1 -
712 =
512 Number of marbles left after giving to her brother and her neighbour = 5 u
Number of marbles left after her mother gave her another 7 marbles = 5 u + 7
5 u + 7 = 42
5 u = 42 - 7
5 u = 35
1 u = 35 ÷ 5 = 7
Number of marbles that Diana had at first
= 12 u
= 12 x 7
= 84
Answer(s): 84
