#3/5# is #30%# of what number?

2 Answers
Jul 8, 2017

2

Explanation:

If #3/5=30%#, then #10%=3/5-:3=3/(5*3)=3/15#

So to get from #10% to 100%# we multiply by 10, so #100%=10*3/15=30/15=2#

Proof:
#2/100=0.02, 0.02*30=0.6=3/5#

Jul 8, 2017

#2#

Explanation:

You can form an equation to show where #3/5# comes from.

Let the unknown number be #x#

#30%# of that number works out to be #3/5#

#30/100 xx x = 3/5" "larr# write it in maths

Isolate #x# by multiplying both sides by #100/30#

#color(blue)(cancel100/cancel30) xx cancel30/cancel100 xx x = color(blue)(cancel100^20/cancel30^10)xxcancel3/cancel5#

#x = 20/10 =2#

You can also treat this as a direct proportion.

#3/5 = 0.6#

#0.6# represents #30%#, then what value represents #100%#?

#x/100 = 0.6/30" "(larr "number")/(larr"percent")#

#x = (100xx0.6)/30#

#x =2#