Maya has 2x as many white beads as black beads. After using 40 white and 5 black to make a necklace she has 3x as many black beads as white. How many black beads she started with?

Question

1572 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-09-26T06:15:39

She started with $23$ black beads.

Suppose Maya has $B$ black beads and so has $2B$ white beads.

She used $5$ black beads and $40$ white beads,

so she was left with $(B-5)$ black beads and $2B-40$ white beads.

Now as she has $3$ times as many black beads as white,

$B-5=3xx(2B-40)$ or

$B-5=6B-120$ or

$120-5=6B-B$ or

$5B=115$ i.e. $B=115/5=23$

Hence, she started with $23$ black beads.