arithmetic
posted by Anonymous on .
the average weight of 20 women is 130 pounds. if the average weight for 3/4 of these women was 140 pounds, what was the average weight, in pounds, for th rest of the women?

20*120=15*140 + 5*W
solve for W 
3/4 of the women is 20*3/4, or 15 women
If the average of all of the women is 130lbs, then the total weight is 20*130 = 2600lbs
The average of those 15 women is 140lbs. So 2600  15*140 is the weight left for the other 5 women.
2600  15*140 = 500
Find the average of those 5 women by dividing 500/5.
500/5 = 100lbs 
100