15h + 80 = 140
If you wanted to solve how many hours he worked:
15h + 80 = 140
15h = 60
h = 4.
1/7 = 0.14285714
rounded to the nearest thousandth, it would be 0.143
Jeff received 280$ from his mother
Such questions are the simplest as it needs you to just write the conditions accordingly which then simplifies and provides you the answer.
This question can be solved using two tricks which are shown below:-
Trick 1 :
1 – 1/4 = 3/4 (used for the 1st 7 days)
1/4 – 410 (used for 8th and 9th days)
(3/4)/7 ——- (1/4 – 10)/2
(3/4) x (2/7) = 3/14 ——- (1/4 – 10)
1/4 – 3/14 = (7 – 6)/28 = 1/28 ——- 10
28/28 ——- 10 x 28 =$ 280
Trick 2 :
7 days ——- 3/4
1 day ——- 3/28
2 days ——- 6/28
6/28 ——- (1/4 – 10) = 7/28 – 410
1/28 ——- 10
28/28 ——- 10 x 28 = $280
Thus Jeff received 280$ from his mother.
Learn more about simple math here :
brainly.com/question/23678
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Biased because the survey was conducted in a limited field of people aka health club which does not include other people, perhaps an unhealthy club? Or the people who are not a part of the health club? Or people who do not care about their health?