जॉइन Examsbookउत्तर : 4. "3"
A class consists of both boys and girls along with a teacher. After a class, the teacher drinks 9 litres of water, a boy drinks 7 litres of water and a girl drinks 4 litres of water. If after a class 42 litres of water was consumed, find the number of girls in the class ?5
प्र: A class consists of both boys and girls along with a teacher. After a class, the teacher drinks 9 litres of water, a boy drinks 7 litres of water and a girl drinks 4 litres of water. If after a class 42 litres of water was consumed, find the number of girls in the class ?
- 18false
- 26false
- 35false
- 43true
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उत्तर : 4. "3"
व्याख्या :
Answer: D) 3 Explanation: Given teacher drinks 9 ltrLet number of boys be 'A'.Let number of girls be 'B'.Boy drinks 7 ltr and girl drinks 4 ltrAfter class total water consumed = 42 ltrThen,9 + 7A + 4B = 42=> 7A + 4B = 33By trial and error method,The only integers which satisfy the equation is A = 3 and B = 3Therefore, number of girls in the class = 3.