A, B and C have a total of 100 yuan. Among them, a is 3 yuan less than B twice and C is 7 yuan more than B three times. How much does a, B and C have? A, B and C have 103 yuan in total. Among them, a is 3 yuan less than B twice, C is 7 yuan more than a three times. How much does a, B and C have?

A, B and C have a total of 100 yuan. Among them, a is 3 yuan less than B twice and C is 7 yuan more than B three times. How much does a, B and C have? A, B and C have 103 yuan in total. Among them, a is 3 yuan less than B twice, C is 7 yuan more than a three times. How much does a, B and C have?

A plus 3 yuan is twice as much as B, that is, a, B and C have a total of 100 + 3 yuan
C minus 7 yuan is three times of B, that is, a total of 100 + 3-7
So B is: (100 + 3-7) / (1 + 2 + 3) = 16
A: 16 * 2-3 = 29
C: 16 * 3 + 7 = 55

In order to find out the two light balls, they were weighed three times with a balance. The results are as follows: the first time: ① + ② is heavier than ③ + ④; the second time: ⑤ + ⑥ is lighter than ⑦ + Ⅷ; the third time: ① + ③ + ⑤ is as heavy as ② + ④ + Ⅷ. The two light balls are ()
A. ①、④B. ③、⑧C. ②、⑤D. ④、⑤

Because ① + ② is heavier than ③ + ④, there is at least one light ball in ③ and ④. Because ⑤ + ⑥ is lighter than ⑦ + Ⅷ, there is at least one light ball in ⑤ and ⑥. Because ① + ③ + ⑤ and ② + ④ + Ⅷ are the same weight, we can know that the number of the two light balls is ④ and ⑤

In a test, Xiaoming got 10 wrong answers and Xiaogang got 8 wrong answers. The number of right answers of Xiaoqiang is equal to the sum of the number of right answers of Xiaoming and Xiaogang, and Xiaoqiang got 3 wrong answers. There are three questions in this test______ A question

10 + 8-3 = 15 (questions); answer: there are 15 questions in this test. Or: if there are x questions in this test, then: & nbsp; & nbsp;; (X-10) + (X-8) = x-3 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp