Problem Solving

When 2/3 of the garments in a shipment were inspected, 18 of the garments passed inspection and the remaining 2 garments failed. How many of the uninspected garments must pass inspection in order that 90 percent of the garments in the shipment pass?

A. 10
B. 9
C. 8
D. 7
E. 5

Please explain...


Got this question correct but would like to see a futher explaination..

Thanks.

We want 90% of the total shipment to pass inspection. We know from the question that 20 of the garments were inspected (18 + 2) and that represents 2/3 of the shipment.

Therefore we know that the entire shipment consists of 30 garments. Again, we want 90% of those to pass, or 27. Since we know that 18 have already passed, we need 9 more.

Good luck, hope this helps.