Maria and Farida had 250 beads altogether. After Maria used 18 beads to make a bracelet and Farida gave away 2/5 of her beads, they have the same number of beads left. How many beads did Maria have at first?



Answer :

m + f = 250 ;
m - 18 = ( 3 / 5)f ;

5m / 5 - 90 / 5 = 3f;
5m - 90 = 3f ;
5m - 3f = 90;
But, f = 250 - m;
5m - 3( 250 - m ) = 90 ;
5m - 750 + 3m = 90 ;
8m = 840;
m = 840 ÷ 8 ;
m = 105( beads for Maria );
f = 250 - 105 ;
f = 145 ( beads for Farida ) ;