If 45% of a number is 36, then the number is  Choose the correct choice from the following choices.
A) number is 60 B) number is 70 C) number is 90 D) number is 80 E) None of these
Solution:   Let "a" be the number we seek. We get   45% × a = 36   2 × 45% × a = 2 × 36 = 72   90% × a = 72   10% × a = 72 : 9 = 8   100% × a = 8 × 10 = 80   a = 80   Answer number is 80
<result>D</result>
If 45% of a number is 36, then the number is