1. The average weight of Xiaodong and Xiaojun is 32kg, that of Obana Xiaojun is 28kg, and that of Xiaodong and Xiaohua is 30kg. What is the average weight of these three students? What are the weights of these three students?

(1) The weight of Xiao Dong and Xiao Jun is 32× 2 = 64 kg.

The weight of Obana Xiaojun is: 28× 2 = 56 kg.

The weight of Xiaodong and Xiaohua is 30× 2 = 60 kg.

The weights of Xiaodong, Xiaojun and Xiaohua are: (64+56+60) ÷ 2 = 90kg.

The average weight of these three students is: 90 ÷ 3 = 30 kg.

(2) Xiao Dong's weight: 90-56 = 34kg.

Small unit weight: 90-60 = 30 kg

Small flower weight: 90-64 = 26kg.

123456789 Nine numbers, one number in each bracket makes the formula valid (each number cannot be reused).

The first question:

( )( )+( )-( )=( )

( )*( )=( )( )

The second question:

( )( )( )( )*( )=( )( )( )( )

The first question: (1) (3)+(2)-(7) = (8)

⑹*⑼=⑸⑷

Question 2: (1) (7) (3) (8) * (4) = (6) (3) (6)

Or: (1) (9) (3) * (4) = (8) (5) (2)

Wang Ran runs along a 60-meter-long rectangle for 6 minutes, running 120 meters per minute to find the width.

A * * * ran away:

120 * 60 = 720m

720\60= 12 (m)

That's all. what do you think?