# GMAT Preparation Math Review Arithmetic Percent Solutions Part 1

Updated on May 27, 2012

## 1

Due to 1% rise in the expense, they have now 2500*(100+1)/100 = \$2525 expense.These expenses due to 2% increase in inflation rate now 2525*(100+2)/100=\$2575.5.

Walter family needs to have budget cut of 2575.5-2500= \$75.5

## 2.

Michael’s first investment contributed to profit in the amount of 500*(100+10)/100=\$50. Therefore his second investment must have generated 100-50 = \$50 the rest of his profit. His second investment needs to generate 1000*(r/100) = 50

If you resolve the equation for r, you will have r=5%

## 3.

50*(20/100) = 10 passengers got off the bus at the first stop. 50-10=40 passengers remained on the bus after the first stop. 40*(10/100) = 4 another 4 passengers got off the bus at the second stop. Therefore 40-4=36 passengers left on the bus.

## 4.

50% of water ratios from half-filled container translate to 50% water for overall to start with. Another 25% overall will come from the mixture. Total water percentage is now 75%. Therefore only 100-75=25% will be alcohol overall.

## 5.

Total number of questions asked ion all 3 tests 50+80+100=230. In order to get qualify passing grade Sam needs to answer 230*(50/100)=115 correctly. He has answered 20+36=56 questions correctly in his 2 tests. He needs to answer 115-56= 59 questions correctly on his 3rd test.

## 6.

Last year milk production was 1,100*(100+10)/100=1,000. Therefore 5 cows’ addition caused 1,100-1,000=100 gallons increase in the milk production. Each cow gives 100/5=20 gallons milk per year.

## 7.

Original value is 240/ (100+20)/100= 200. If you decrease 200 by 30%, It will be 200*(100-30)/100=140.

## 8.

Michael’s merchandise excluding tax amount 1,000*(100-7)/100=\$930. Restocking fee will be applied to 930*(5/100) = \$46.5. Michael lost \$46.5

## 9.

If x percent of women in the party then x*(100+20)/100=x*1.2 men are in the party. Total is x+1.2x and equal to 44. If we resolve the equation for x, we have x=20. We have 1.2*x=1.2*20=24 men in the party. If 10 couple lives 24-10-5=9 men will be left in the party.

## 10.

\$1,000 of initial investment will earn (1,000*(100+10)/100=\$1100 in first year.

\$1,100 of investment in second year will earn 1,100*(100+10)/100=1210 in second year.

\$1210 of investment in 3rd year will earn 1,210*(100+10)/100=1331