AAPL wrote: ↑

Fri Feb 12, 2021 3:02 am

Magoosh

In 2004, 2,400 condos sold, 15% of the total housing units sold that year. How many units sold in 2004 were not condos?

A. 16,000
B. 13,600
C. 12,400
D. 11,200
E. 8,600

OA B

We can solve the question with equivalent ratios

If 15% of the units sold WERE condos, then 85% of the units sold new NOT condos.
So we want to determine the number of sold units that represent 85% of all units sold

We'll use the ratio: (number of units sold)/(percent of units sold)
Let x = the number of NON-CONDO units sold that represent 85% of all units sold
We get: (2400)/(15) = (x)/(85)
Cross multiply to get: (15)(x) = (2400)(85)
Divide both sides by 15 to get: x = (2400)(85)/(15)
Evaluate: 13,600

Answer: B

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We can also solve this with a little number sense


If 15% of the units sold WERE condos, then 85% of the units sold new NOT condos.

GIVEN: 2,400 represents 15% of the total housing units sold that year
So, 4,800 must represent 30% of the total housing units sold that year
And 9,600 must represent 60% of the total housing units sold that year
And 14,400 must represent 90% of the total housing units sold that year
Oops, we went too far. We need to subtract 5% worth of housing units to get down to the desired 85%

If 2,400 represents 15% of the total housing units sold that year. . .
Then 800 must represent 5% of the total housing units sold that year

So, 85% of the housing units sold = 14,400 - 800 = 13,600

Answer: B

Cheers,
Brent