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吴林大会

你好，请教一道小五的数学题，实在的伤脑筋，请高手帮助。

Alvin and Ken earned $6425 altogether .1/5 of Alvin's monthly salary was $75 more than 1/6 of Ken's monthly salary.How much money did Alvin earn each month?

davidbin

Assume Ken's monthly salary is 6u, then Alvin's monthly salary is 5u+5x75 = 5u +375
11u + 375 = 6425 -----> 1u = 550
Alvin's salary is 5u+375 = $3125

吴林大会

5 days were used to print some wordsheets.The number of worksheets printed on the Tuesday was 2/3 of those printed on the Monday. The average number of worksheets printed on Wednesday, Thursday and Friday was 44 more than 3/4 the number of worksheets printed on Monday.if the total mumber of worksheets printed from Tuesday to Friday was 3643 ,how many worksheets were printed on Monday?

静雯

I'm sorry. But can you check your question again?

Solution:

Let the worksheets printed on Monday be 12u.
Then the worksheets on Tuesday is 8u, the average number worksheets printed on Wednesday, Thursday and Friday is 9u+44. Thus the total number printed from Tuesday to Friday is 8u+3(9u+44)=35u+132.
3643-132=3511
u=3511/35 is not a whole number. According to my understanding, the number of worksheets should be whole number. Is that right?
After you solved u, you can get the number of worksheet printed on Monday.

cjj82949321

GIVEN the  equation of a line is -8x+4y=15,find  
      (a)  the  gradient of the line
      (b)   the y-intercept

静雯

cjj 发表于 1-12-2012 16:44
GIVEN the  equation of a line is -8x+4y=15,find  
      (a)  the  gradient of the line
      (b)   t ...

Solution:

(a) When x=0, we get y=15/4.
When y=0, we get x=-15/8.
Points (0, 15/4) and (-15/8, 0) are on this line.

Gradient of the line = (y2-y1)/(x2-x1)=(15/4)/(15/8)=2.

(b) y-intercept is 15/4.
(If you write the line in form y=mx+b, then b is the y-intercept or (0, b) is the y-intercept. I'm not sure about this point, depending on the concept of the y-intercept your textbook stated.)

cjj82949321

THANKS

cjj82949321

A salesman sold 120 digital cameras in june,in july,the sale of digital cameras increased by 15%,find the number of digital cameras sold in july.
  (b)   james and his friends paid $135.90 for a meal,this amount included the 10%  service charge,find the amount. james and his friends paid for service charge

静雯

cjj 发表于 2-12-2012 09:11
A salesman sold 120 digital cameras in june,in july,the sale of digital cameras increased by 15%,fin ...

(a)  120*(1+15%)

(b)  Meal fee = 135.90/(1+10%)        

Service fee = Meal fee *10% = 135.90/(1+10%) * 10%