Mary had some coins at first. She gave 110 of her coins to her sister and 14 of her coins to her neighbour. After that, her mother gave her another 20 coins. She had 111 coins in the end. How many coins did Mary have at first?
Fraction of coins left after giving to her sister and her neighbour
= 1 -
110 -
14 = 1 -
220 -
520 = 1 -
720 =
1320 Number of coins left after giving to her sister and her neighbour = 13 u
Number of coins left after her mother gave her another 20 coins = 13 u + 20
13 u + 20 = 111
13 u = 111 - 20
13 u = 91
1 u = 91 ÷ 13 = 7
Number of coins that Mary had at first
= 20 u
= 20 x 7
= 140
Answer(s): 140
