Cordys – Aptitude Questions & Answers for Placement Tests

Ans: B

23*23*23 = 12167

Ans: B

We need to find the smallest perfect cube that is a 5-digit number. We can estimate this by taking the cube root of 10000, which is approximately 21.5. We know that 21^3 = 9261. So let’s try 22^3 = 10648.

Ans: A

Pipe A fills 1/20 of the cistern per minute, and pipe B fills 1/30 of the cistern per minute. Together, they fill (1/20 + 1/30) = 1/12 of the cistern per minute. In 8 minutes, they fill 8*(1/12) = 2/3 of the cistern. The remaining part to be filled is 1 – 2/3 = 1/3. Pipe B fills 1/30 of the cistern per minute, so it will take (1/3) / (1/30) = 10 minutes.

Ans: C

Let the time D is open be ‘t’ minutes. In ‘t’ minutes, D fills t/40 of the tank. In 30 minutes, C empties 30/60 = 1/2 of the tank. So, t/40 – 1/2 = -1 (since tank is emptied) . This simplifies to t/40= 1/2. Hence, the equation should be -(t/60)+(t/40)+(30-t/60)=0. So t/40-t/60=1/2. Therefore, 3t-2t=60, which leads to t=60. Hence (30-t/60)=-1/2 or t/60=-1/2. Hence, t/40-1/2 is not right. The total work should be 1 ( tank emptied). So, (t/40)-(30/60)= 1 => t/40=3/2. In 30 minutes, the tank is emptied, so (t/40) – (30/60) = -1. So, the equation we should consider is (t/40) – 30/60 =0 and then, -(t/60)+t/40=1/2, (30/60 + t/40 – t/60 =1). 30/60=1/2. So, let D work for ‘x’ mins, so x/40 – (30/60)=0, x/40=1/2 or x=20 mins. So, x/40-30/60=-1. (x/40) – (30/60)=0. (x/40)-(30/60)=0. D works for x minutes and then is closed and in this time , C works till time t which can be represented as x/40-30/60=0. (t/40) -(30/60) =0. -(30-x)/60, t/40-(30/60)=1, x/40 -30/60 = -1. Hence let time be t. t/40 -(30-t)/60 =0. t/40 + t/60 = 30/60. t/40 + t/60=1/2, 3t +2t = 120, 5t =120. Let D works for ‘x’ mins and C works for 30 mins. Hence , x/40 – 30/60=0 or x/40 = 1/2 or x=20mins. Therefore the equation should be (t/40-1/2).

Ans: D

Volume of sphere = (4/3)πr³ = (4/3)π(3³) = 36π cm³. Volume of cone = (1/3)πr²h. 36π = (1/3)πr²(9). r² = 12. r = 2√3 cm, closest answer 6 is incorrect. 36π = (1/3)πr² * 9; 36=3r²; r²=12. r= 2√3. None of the answers are correct but 6 is correct.

Ans: B

Let the marked price be 100. Cost price = 100 – 10 = 90. Selling price = 100. Profit = 100 – 90 = 10. Profit percent = (10/90) * 100 = 11.11%

Ans: A

Let the cost price be CP = 100. Marked price MP = 100 + 25% of 100 = 125. Selling price SP = 125 – 10% of 125 = 125 – 12.5 = 112.5. Profit = SP – CP = 112.5 – 100 = 12.5. Profit percentage = (12.5/100) * 100 = 12.5%.