Any one know the answer to this math question?

Question

Judy had a number of raisins. After eating one, she gave half the remainder to her sister. After eating another raisin, she gave a third of what was left to her brother. Judy now had only six raisins left. How many raisins did she start with?

Answer 1

She started with 21.
21 - 1 = 20 (eats one)
20 / 2 = 10 (1/2 go to sister, so left with 1/2 for herself)
10 - 1 = 9 (eats one)
9(2) / 3 = 6 (1/3 go to bro, so left with 2/3 for herself)

Answer 2

The best way to solve this is by working backwards.

At the end Judy had six raisins. Thus, before giving one third to her brother, she must have had 9 (1/3 of 9 is 3... this leaves her with 6). Before eating one, then, she had 10. Before giving half to her sister, she must have had 20. Since she ate one before that, she started with 21.

Check: 21 -1 = 20
20 - (1/2)20 = 20 - 10 = 10
10 - 1 = 9
9 - (1/3)9 = 9 - 3 = 6

Answer 3

Starting by the end
if Judy gave to her bro 1/3 while she had six remaining, thenJudy must had thrice the amount
then 6 multiply by 3 gives 18
add one to 18 because dont forget she ate one before giving to her bro gives=19
before that Judy hav her 1/2 the amount of raisins left after eating one,
then is 19 times 2 =38
add one it gives 39

Answer 4

Judy had a total of 39 raisins to start with.

Answer 5

21

Answer 6

21

Start with what we know. We know we end with six, so we'll start there. We also know that six is two thirds of the next number we need to know.

6=2/3(x)

Find x, we multiply by 3/2 (each side), and get 18/2=x, or 9=x.

Add 1, per the question, to get 10. Multiply by 2, get 20, add one more, to get 21.

Just working the question backward.