An urn contains forty red chips and sixty white chips. Six chips are drawn out and discarded, and a sev- enth chip is drawn. What is the probability that the sev- enth chip is red

The probability that the 7th chip is red = 0.4

Step-by-step explanation:

Given that;

an urn contains 40 red chips and 60 white chips

6 chips are randomly drawn and discarded and a 7th chip is drawn,

lets consider E as the the event that represent the 7th chip is red.

so probability that 7th chip is red will be;

P(E) = ⁶∑ ×  /  

= × + ×  + ......+  /

= [ 2002554400 + ..... + 130504920 ] /

= 44821170240 / (1192052400)(94)

= 44821170240 / 112052925600

= 0.4

Therefore the probability that  the 7th chip is red = 0.4

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles