a, b, c, and d are positive consecutive integers and a

Question

a, b, c, and d are positive consecutive integers and a < b < c < d. If the product of b, c, and d is twice that of a, b, and c, then bc =

A. 2
B. 6
C. 12
D. 20
E. 30

sanjitscorps18 · Accepted Answer

1. a, b, c, and d are positive consecutive integers 2. a < b < c < d 3. bcd = 2 x abc => d = 2a The four number are a, b, c, 2a => a + 3 = 2a => a = 3 hence b = 4 and c = 5 Hence bc = 20 Option D

shalin23 · Answer

I didn't understand how you got a+3=2a?

aanchal20 · Answer

Hey, 
 
 As a,b,c,d are positive consecutive integers so a+3 will get to d and the relation between a n d is d=2a.

e3thekid · Answer

a = 3
b = 4
c = 5
d = 6

b • c • d = 2 • (a • b •c) 
d = 2a

bc = (4)(5) = 20

IMO Option D

Posted from my mobile device

sanjitscorps18 · Answer

Saw this post today, missed it earlier.

a + 3 represents the 3rd consecutive number after a. 
Since we are given consecutive (a, b, c, d) numbers to work with, we can write a + 3 = d
Also, since d = 2a we have a + 3 = 2a 
Hope it's clear!!

PrafulLata · Answer

a, b, c, and d are positive consecutive integers and a < b < c < d. If the product of b, c, and d is twice that of a, b, and c, then bc =?

Since a, b, c, and d are positive consecutive number, we can write
b = a+1
c = a+2
d = a+3

We are given that product of b, c, and d is twice that of a, b, and c
so (a+1)(a+2)(a+3) =2 * a*(a+1)*(a+2)
after simplifying we get 
a+3 = 2a
 a = 3
so, b = 4 and c =5 and b*c = 20

Therefore option D is correct answer.

a, b, c, and d are positive consecutive integers and a < b < c < d. If

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions