2. After the price increase, the value is 2,000 x (1+50%) = 3,000 yuan, and then 20% discount is 3,000 x 0.8 = 2,400. So promote to make money and earn 400 yuan.
3.( 1) Since the manufacturer wants to earn 20%, the purchase price is100x (1+20%) =120 yuan. (2) Because retailers need to add 10% to the purchase price to earn 10%, the retail price is120x (1+10%) =132 yuan.
4, A: B = (1/2): (2/3) = 3: 4, B: C = 2: 5, if b=2, then c=5, similarly a=3/2,
So a: b: c = 3/2: 2: 5 = 3: 4: 10.
5. If the interest rate is a, it is1000+1000 x0.8x2 =1032.8, a=2.05%.
6. If there are 2a people in the calligraphy group, then there are 3a people in the science and technology group, 8a people in the painting group, and the painting group is more than the science and technology group 10, that is, 8a-3a = 10, so a=2, so there are 6 people in the science and technology group, 4 people in the calligraphy group and 16 people in the painting group.
Typing is very hard, I hope the landlord will adopt it! ! ! Ask if you don't understand!