How to explain 108 + 109 + 110 + 111 + 112 + 113 + 114 = () * () = ()

How to explain 108 + 109 + 110 + 111 + 112 + 113 + 114 = () * () = ()

108+109+110+111+112+113+114=(111)*(7)=(777)
108+3=111
109+2=111
110+1=111
112-1=111
113-2=111
114-3=111
The average of these seven numbers is 111

111 112 113 114 115 116 113

114

The price of a drug is 56.10 yuan per box, 15% lower than the original price___ Yuan

Suppose the original price is x yuan, according to the meaning of the question: (1-15%) x = 56.10, the solution is: x = 66, so the answer is: 66

The price of a drug is 56.10 yuan per box, 15% lower than the original price___ Yuan

Suppose the original price is x yuan, according to the meaning of the question: (1-15%) x = 56.10, the solution is: x = 66, so the answer is: 66

Now the price of a drug is 56.10 yuan per box, which is 15% lower than the original price. How much is the original price?

Original price
56.10÷（1-15%）
=66 yuan

A simple algorithm of multiplying 127 by 15 / 26 of mathematics problems in Volume 1 of grade 6

Change 127 into (26 times 5 minus 3) and do it according to the law of distribution of multiplication! You will succeed!

Oxygen accounts for 21% of the air and phlegm accounts for 39% of the air. How many liters of oxygen and phlegm are there in 300 liters of air?
Air is a mixture of oxygen and phlegm. Oxygen accounts for 21 percent of the air and phlegm accounts for 39 percent of the air. How many liters of oxygen and phlegm are there in 300 liters of air?

Oxygen: 300 × 21% = 63 (L)
Nitrogen: 300 × 39 / 50 = 300 × 78% = 234 (L)
A: 300 liters of oxygen contains 63 liters of oxygen and 234 liters of nitrogen
PS: it's called nitrogen, not phlegm

How to do the math problem of grade six in primary school
1. Boss Li sold two TV sets today, both of which are 2400 yuan. One TV set has 1 / 5 profit and the other one has 1 / 5 loss. Please help boss Li calculate whether he has made or lost
When the distance between the two vehicles is 4 km, a takes 2 / 3 of the whole journey and B takes 3 / 5 of the whole journey. How many km is the distance between the two vehicles
3. There are two books. The number of the second book is 3 / 4 of the first one. If you take 21 books from the second one, the number of the second book is 2 / 5 of the first one. How many meters is the second one?
Can you tell me the answer and the method? I don't understand the method

1. 2400 × 1 / 5 = 480. Earned 480 yuan
2400 ÷ 4 / 5 = 3000.3000-2400 = 600
All in all, I lost 120 yuan
2、4÷（2/3-3/5）=60Km
3. 21 △ (3 / 4-2 / 5) × 3 / 4 = 45 copies

It costs 168 yuan to buy one football and five volleyball. Volleyball is 48 yuan cheaper than football. How much is the unit price of volleyball and football?

Suppose a volleyball is x yuan, then the price of football is x + 48 yuan; 5x + X + 48 = 168, 6x + 48 = 168, 6x = 120, x = 20, football = 20 + 48 = 68 yuan / piece

The school has 630 science and technology books and story books, of which 20% are science and technology books. It has bought a batch of story books, of which 3 / 20 are science and technology books. How many are there now?

630 * 20% = 126 (copies) 126 / 3 / 20 = 840 (copies)