Question

2 men start from 2 places 600km apart and travel towards each other, the first travelling 5km/h faster. they meet after 8 hours.find te speed of the fastest man

Answer 1

600/8 = 75
since they are moving in opposite direction their relative velocity is equal to sum of individual velocity

Answer 2

let their speeds be x and x-5 units respectively
then by the prob
x+x-5=600/8
2x-5 =75
2x=80
x=40
so speed of the fastest one is 40km/h

Answer 3

thank you matricked

Answer 4

YW

Answer 5

how about this one.
mary noticed that she had 104 coins made up entirely of 20c and 5c coins that totalled exactly $10. how many of each type of coin did she have?

Answer 6

20¢ coins??? 19th century USA isn't it?

Answer 7

Aussie coins

Answer 8

oops sorry for my USA centric outlook :-(

Answer 9

Let number of 20 cent coins be x
and the number of 5 cent coin be y

x + y = 104
x/5 + y/20 = 10

Solve for x and y.

Answer 10

Or if you would like you can write the second equation as
0.2x + 0.05y = 10

Answer 11

Thanks!
One last question.
John is twice as old as Mary. five years ago he was three times as old. What is Mary's age now?

Answer 12

Let M be Mary's age and J be John's age
J = 2M
5 years ago, John would have been (J-5) years old and Mary (M-5) years old
J - 5 = 3(M - 5)

Eliminate J and solve for M

Answer 13

Nice work, thank you all!!

Answer 14

You are welcome.

Answer 15

COIN PROBLEM
t = twenty cent pieces
n = 5 cent pieces (nickels)

t + n = 104
.2 t + .05 n = $10.00

32 20¢ pieces
72 5¢ pieces

32*.2 = 6.40
72*.05 = 3.60
Total = 10.00

Answer 16

Thank you Wolf1728

Answer 17

u r welcome :-)

Answer 18

By the way, @remo
\(\Huge\bf \color{yellow}{Welcome~to~OpenStudy!!}\hspace{-310pt}\color{cyan}{Welcome~to~OpenStudy!!}\hspace{-307.1pt}\color{midnightblue}{Welcome~to~\color{purple}{Open}}\color{blue}{Study!!}\)

Answer 19

john is twice as old as mary. 5 years ago he was 3 times as old. what is mary's age now?
could anyone please show me how to solve this.