Ok i suck at probability and i relay need to work some thigs out beofr tomrow. first, how do i use the npr/ncr button on the calc to work out combs/perms...im confused at when to use that method and how to do it.
also can some1 check these answers for me:
(a) On a bridge, the toll of 2.50 is paid in coins collected by a machiene. the macheien only accpets $2, $1 and 50c coins.
(i) list the combinations used to pay the 2.50
(ii) jill has 3 two dollar coins, 6 one dollar coins and 2 50c coins. she selects 2 at random. wat is the robability the she selects exactly 2.50?
(iii) at the end of the day the macheine contains x two-dollar coins, y one dollar coins and w 50c coins. write an expression for the total value of coins
I:
1,1,50c
50,50,50
2,50
II: 2/10x2/9 = 2/45
III: v=x+y+w
also can some1 check these answers for me:
(a) On a bridge, the toll of 2.50 is paid in coins collected by a machiene. the macheien only accpets $2, $1 and 50c coins.
(i) list the combinations used to pay the 2.50
(ii) jill has 3 two dollar coins, 6 one dollar coins and 2 50c coins. she selects 2 at random. wat is the robability the she selects exactly 2.50?
(iii) at the end of the day the macheine contains x two-dollar coins, y one dollar coins and w 50c coins. write an expression for the total value of coins
I:
1,1,50c
50,50,50
2,50
II: 2/10x2/9 = 2/45
III: v=x+y+w
