im stumped...?

Question

everyone at the toys R us confrince spoke one or more of these three languages:English, Japanese, Swahili. Seven of the people spoke english, seven spoke japanese and seven spoke swahili.
two of the people spoke english and japanese, four of the piople spoke english and swahili and three of the people spoke swahili and japanese. only one person spoke all three lanuages. (some people have been counted more than once)
1. how many people participated in the conference?

thank you for helping i have been stuck on this all day i think i have an answer 1) 10 2)0 but i want to double check thanks
2. how many of then spoke only english?

Answer 1

There are 3 languages. You know seven people spoke English, right? Of those seven:
One spoke all 3: 1 E/S/J
Four spoke English and Swahili, but one of them is the person who spoke all 3, so ignore him: 3 E/S
Two spoke English and Japanese, but one is the person who spoke all 3, so ignore him: 2 E/J
That's six people. That leaves one, who only spoke English: 1 E

Of the seven Swahili speakers, one spoke all 3. We already know about him.
Three others also spoke English but not all 3, but we already talked about them above.
Three others spoke Swahili and Japanese, but one is the trilingual. So 2 S/J.
That makes six. So there must be one Swahili-only speaker: 1S

Of the seven Japanese speakers, one is the tri-lingual.
We already know there are two more E/J and 2 more S/J.
That makes 5. So there are two Japanese-only speakers: 2J

Add them up:
1 E/S/J
3 E/S
2 E/J
1 E
2 S/J
1 S
2 J
Total = 12.

Answer 2

11,4 spoke eng

ack i had to edit this-nobody only spoke english, everyone else is wrong...its 21 to simplify the problem brake it down like this
E J S
2 2 (2)
4 (4) 4
1 1 1
__ ___ ___
7 + 7 + 7 = 21

remember 7 spoke eng, 7 spoke jap, and 7 swahili, its a trick question, if the question didn't say "Seven of the people spoke english, seven spoke japanese and seven spoke swahili." than the answer would be 11.

Answer 3

all of them spoke english

Answer 4

1 - e/j
2 - e/j
3 - e/s
4 - e/s
5 - e/s
6 - e/s
7 - e/j/s
8 - j only
9 - j only
10 j only
11 j only
12 s only
13 s only
7e / 7j / 7s
no e only

Answer 5

Ask your teacher.