BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Probability

Expert replies
by evansbd » Tue Jul 22, 2008 10:59 am
In a basketball contest, players must make 10 free throws. Assuming a player has 90% chance of making each of his shots, how likely is it that he will make all of his first 10 shots?

a) 10%
b) 25%
c) 35%
d) 45%
c) 55%


How many randomly assembled people do u need to have a better than 50% prob. that at least 1 of them was born in a leap year?

a) 2
b) 3
c) 4
d) 5
c) 7


I generally know how to do each problem, but I'm not sure if I could do each without a calculator very quickly.
Join the discussion
Source: — Problem Solving |

by egybs » Tue Jul 22, 2008 11:13 am
We're looking for .9^10

There may be some really easy shortcut... but it's actually pretty quick to roughly estimate it out.

Just start with 1, and remove 10%... then remove 10% from that number.. then remove around %10 from that number... and so on... do this a total of 10 times. This shouldn't take more than 60 seconds to do and gets you really close to the answer.

.9
.81
.73
.66
.6
.54
.5
.45
.4
.36

So, C.
Join the discussion