40 divided by (1-20%)=50.
60 divided by (1+20%)=50.
25% of a number is 8 more than its 20%. What's this number?
8 divided by (25%-20%)= 160.
(3) The current price of a dress is 255 yuan, which is 15% less than the original price, saving (45) yuan.
255 divided by (1- 15%)=300 yuan, which is the original price.
300* 15%=45 (yuan)
(4) 50% of a number is 40 and greater than 0.3. What's this number? (Equation)
Solution: let this number be X.
50%X=40+0.3
50%X=40.3
X=80.6
60% of a number is 7 more than its 25%. What's this number? (Equation)
Solution: let this number be X.
60%X-25%X=7
35%X=7
X=20
(6) The sum of 30% of a number and its 15% is 153. What's this number? (Equation)
Solution: let this number be X.
30%X+ 15%X= 153
45%X= 153
X=340
(7) Multiply 2.5 of x by 8.5, which is equal to 20% of 80, and find X (equation).
2.5X+8.5=80*20%
2.5X= 16-8.5
X=3