Which of the following is equivalent to \(\dfrac{8!+9!}{10!}?\)

This topic has expert replies
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8086
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members
Vincen wrote:
Tue Oct 06, 2020 7:19 am
Which of the following is equivalent to \(\dfrac{8!+9!}{10!}?\)

A. \(\dfrac1{72}\)

B. \(\dfrac9{100}\)

C. \(\dfrac19\)

D. \(\dfrac9{10}\)

E. \(\dfrac{17}{10}\)

Answer: C

Solution:

Factoring out 8! from the numerator and denominator, we have:

8!(1 + 9) / [8!(9 x 10)]

After canceling 8! from the numerator and denominator, we have:

(1 + 9) / (9 x 10) = 10/90 = 1/9

Answer: C

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage