Agirl had 20 coins in nickels and dimes whose sum was $1.40. she spent 65cents , using 8 coins. she now has ? nickels.

9 Nickles

Step-by-step explanation:

Let n = number of nickles and d = number of dimes

d + n = 20 -----------(1)     [ total number of coins 20 ]

Dimes = $0.10

Nickles = $0.05

0.1d + 0.05n = $1.40 ---------- (2)         [20 coins worth $1.40]

Since d + n = 20

∴ n = 20 - d

Let's substitute n in equation (2)

0.1d + 0.05(20-d) = 1.40

0.1d + 1 - 0.05d  = 1.40

0.1d + 0.05d = 1.40 - 1

0.05d = 0.4

d =

d = 8

Now put value of d in equation (1)

n + 8 = 20

n = 20 - 8

n = 12

Let's check 8(0.1) + 12(0.05)  = $1.40

Now she spent 65 cents using 8 coins.

The only combination of 8 coins worth $0.65 is

5d + 3n = $0.65

Hence, she used 5 dimes and 3 nickles.

Now she has 12 - 3 = 9 Nickles

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560

27/4x^6 y^8

step-by-step explanation:

4(3x^2y^4)^3 (2x^3y^5)^4

=

108x^6 y^12 /16x^12 y^20

=

108 /16x^6 y^8

=

27 /4x^6 y^8