Question #bd490

2 Answers
Apr 7, 2017

See the entire solution process below:

Explanation:

"Percent" or "%" means "out of 100" or "per 100", Therefore 45% can be written as 45/100.

When dealing with percents the word "of" means "times" or "to multiply".

Finally, lets call the number we are looking for "n".

Putting this altogether we can write this equation and solve for n while keeping the equation balanced:

72 = 45/100 xx n

color(red)(100)/color(blue)(45) xx 72 = color(red)(100)/color(blue)(45) xx 45/100 xx n

7200/color(blue)(45) = cancel(color(red)(100))/cancel(color(blue)(45)) xx color(blue)(cancel(color(black)(45)))/color(red)(cancel(color(black)(100))) xx n

160 = n

72 is 45% of color(red)(160)

Apr 7, 2017

The number is 160

Explanation:

Calculations with percent can always be done by using direct proportion.

In this case we know that 72 represents 45% and we want to know what number represents 100%

72 " " rarr 45%
x" "rarr 100%

x/72 = 100/45" "larr cross multiply and solve for x

45x = 72 xx 100

x = (72xx100)/45

x = 160" "larr this is the 100%

NOTE:

When we divide 72 " by " 45 we are finding 1%

Once we know the value of 1%, multiply by 100

72/45 xx 100 = 1.6 xx 100 = 160