Quantitative Aptitude - Arithmetic Ability Questions

Part filled in 4 minutes =4(1/15+1/20) = 7/15

Remaining part =(1-7/15) = 8/15

Part filled by B in 1 minute =1/20 : 8/15 :: 1:x 

x = (8/15*1*20) = 1023min = 10min 40sec

The tank will be full in (4 min. + 10 min. + 40 sec.) = 14 min. 40 sec

The given number series is 3, 12, 39, 120, 364

$$\begin{gathered} 3 \\ 3 + 32 = 3 + 9 = 12 \\ 12 + 33 = 12 + 27 = 39 \\ 39 + 34 = 39 + 81 = 120 \\ 120 + 35 = 120 + 243 = 363 (Not 364) \end{gathered}$$

The series follows the following pattern.

4

16 = 42

37 = 12+62

58 = 32+72

81 ≠52+82.

Here every number is based on the digits of previous number. Hence, 81 is the wrong number in the given series.

let length = x and breadth = y then  

2(x+y) = 46         =>   x+y = 23  

x²+y² = 17² = 289  

now (x+y)² = 23² 

=> x²+y²+2xy= 529 

=> 289+ 2xy = 529

=> xy = 120  

area = xy = 120 sq.cm

A's Salary  = 40% of B = 40% of (25% of C) = 40/100[(52/100)*100] % of C = 10% of C.