Answer:
i am pretty sure the total surface area is 580
let, x be the no of coins then according to question.Mary have 3x no of coins and John have x no of coins..
now, 3x+x=180
or,4x=180
or,x=180/4
therefore, x= 45
thus mary has 3×45=135 no of coins...
Answer:
The probability that the last card dealt is an ace is 
.
Step-by-step explanation:
Given : A deck of ordinary cards is shuffled and 13 cards are dealt.
To find : What is the probability that the last card dealt is an ace?
Solution :
There are total 52 cards.
The total arrangement of cards is 52!.
There is 4 ace cards in total.
Arrangement for containing ace as the 13th card is 
.
The probability that the last card dealt is an ace is
Therefore, the probability that the last card dealt is an ace is .
Follow this as an example
An empty swimming pool needs to be filled to the top. The pool is shaped like a cylinder with a diameter of
10 m
and a depth of
1.4 m
. Suppose water is pumped into the pool at a rate of
11 m3
per hour. How many hours will it take to fill the empty pool?
Use the value
3.14
for
π
, and round your answer to the nearest hour. Do not round any intermediate computations.
The formula for the volume of a cylinder is ∏r2h. The problem gives d=10m, so r=5m.
The pool holds (3.14)*52*1.4 m3 = 109.9 m3 of water.
At a rate of 11 m3 per hour:
( 109.9 m3 ) / (11 m3/hr) = 9.990909 hr.
rounding to the nearest hour, this is 10 hours
