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1. A barrel of oil weighs 40 kg. After four fifths of the oil is poured out, the barrel weighs 12 kg. How many kg of oil is there in the barrel? 2. The number of school art group is six more than that of sports group, and the number of sports group is one fifth less than that of art group. The number of calligraphy group is four fifths of that of art group. How many people are there in calligraphy group?
1)(40-12)÷4/5
=28÷4/5
=35kg
2) Art group: 6 ／ 1 / 5 = 30 people
Calligraphy group: 30 × 4 / 5 = 24
Six grade mathematics problem two (have process and result) urgent!
1. Dig out the largest cone in a cube with an edge length of 8 cm and calculate the remaining volume
2. Split a cylindrical wood in half, 30cm in length and 12cm in diameter (after sawing), and calculate the volume of the wood
① 8 × 8 × 8 = 512 CC
4 × 4 × 3.14 × 8 × 1 / 3 ≈ 114 CC
512-114 = 398 CC
② 6 × 6 × 3.14 × 30 = 3391.2 cm3
A total of 20 questions. 5 points for one right question, 0 point for none, 2 points for one wrong question
Xiaoqiang got 64 points. He made as many mistakes as he didn't. how many questions did Xiaoqiang make right?
Suppose that the number of wrong questions is 20-2x
Equation: 5 (20-2x) - 2x = 64
X=3
20-3=14
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