130% of what number is 1170?

1 Answer
Aug 8, 2016

Answer:

#900#

Explanation:

As the number has been increased by 30% to become 1170, we are expecting a number smaller than 1170 as the answer.

DO NOT be tempted to just subtract 30%. 30% of a smaller number is not the same as 30% of a larger number.

One method is to write an equation stating exactly what is asked in the question. "130% of some number is 1170."

#130/100 xx x = 1170#

#x = 1170 xx100/130 " by dividing by 130, we are finding 1%"#

#x = 900#

OR, by direct proportion:

#130/100 = 1170/x#

#x = (100 xx 1170)/130#

#x=900#

[Quick check: 130% =1.3 so #900 xx 1.3 = 1170#]