Find an Olympiad Problem Ask for Explanation 5

You can do the equation.

Let's say my sister bought a sugar x pack for the first time, and my sister is 3 times that of my sister is 3 * x packs.

After buying five pills each, my sister is x+5

The younger sister is 3*x+5

Then columnar. 2*（x+5）=3*x+5

Allocation rate. 2*x+2*5=3*x+5

Tidy up. 2*5-5=3*x-2*x

5=1*x, so x=5

So my sister bought 5 packs.

My sister bought 15 packs.

Olympiad math problems are actually for primary school students to do junior high school students' problems, because primary school has not learned equations, and it is difficult to use primary school students' thinking to solve them.

Let's say my sister buys x candy for the first time, and my sister buys 3x candy.

3x+5=2（x+5）

x=5 for sister: 15

My sister bought 10 and my sister bought 20

Are you sure this is an Olympiad problem?

My sister bought 10 candies and my sister bought 20 candies.

Use the hypothetical method. Suppose the sister buys 5 pieces of candy for the first time, then the sister buys 3 times as much candy as the sister, so use 3*5=15 pieces of candy for the second time, and the sisters buy 5 pieces of candy.

The candy that my sister bought was: 5 + 5 = 10 The candy my sister bought was 15 + 5 = 20 pieces.

20 is exactly 2 times that of 10, so it can be seen that my sister bought 10 candies and my sister bought 20 candies.

My sister buys 10 and my sister buys 20.

Try drawing a line diagram! One copy of my sister's painting and three copies of my sister's painting. After my sister bought 5 pieces of candy, if my sister still wanted to be three times that of my sister, she had to buy 15 pieces, and she only bought 5 pieces, which was twice as less, 5+5=10, which means that 10 is doubled, so it follows that my sister bought 10 pieces, and my sister bought 10 times 2,20 pieces.

Hope it helps.

At least 9 trees. The picture is not very easy to upload.,You need to add me hi.

The volume of soil in the higher part of the place A than the part of the place B = 36 * 5 = 180

A is the same as B, and the number of meters that B usually rises = 180 (36 + 24) = 3

So the number of meters reduced by A = 5-3 = 2 meters.

2 meters. The volume of A is 180 cubic meters more than B, if the two are of the same height, then (36+24)h=180, and the solution is h=3

Let the ground be lowered by h meters compared with the original, and the equation according to the problem is 36 h=24 (5-h).

Solution: h=2

If it is lowered by 2 meters, let it be lowered by x meters, then 36*x=24*(5-x).