Quantitative Aptitude - Arithmetic Ability Questions

Man walked 6 km at 1.5 kmph, again he walked 8 km at speed of 2 kmph and 40 km at a speed of 8kmph
time taken indivisually:
=> 6/1.5 = 4 m
=> 8/2 = 4 m
=> 40/8 = 5 m

Average speed of man= total distance/ total time
=> 54/13 = 4213 kmph

Let the ten's digit be x.

Then, unit's digit = x + 2.

Number = 10x + (x + 2) = 11x + 2

Sum of digits = x + (x + 2) = 2x + 2.

(11x + 2) (2x + 2) = 144

=> 22x^2+26x-140=0

=> (x - 2)(11x + 35) = 0

=> x = 2

Hence, Required Number = 11x + 2 = 24

principal = A=4913,T=3, R=413

P=A1+R100T

 = Rs.4096

Krish’s age = 3A and Vaibhav’s age = 5A

(3A+9)/(5A+9) = 3/4

=> 4 (3A + 9) = 3 (5A + 9)

=> A = 3

Therefore, Vaibhav’s age = 15 years.

For an income of Rs. 8, investment = Rs. 100.

For an income of Rs 6, investment =Rs. (100/8*6) = Rs. 75

Market value of Rs. 100 stock = Rs. 75.

Let x men can do the in 12 days and the required number of days be z

More men, Less days     [Indirect Proportion]

Less work, Less days     [Direct Proportion  ]

 men2x:xwork1:12 :: 12 : z

∴2x×1×z=x×12×12

 ⇒z=3

5% is the rate of interest. 20% of the interest amount is paid as tax.

i.e  80% of the interest amount stays back.

 if we compute the rate of interest as 80% of 5% = 4% p.a., we will get the same value.

The interest accrued for 3 years in compound interest = 3 x simple interest on principal + 3 x interest on simple interest + 1 x interest on interest on interest.

= 3 x (200) + 3 x (8) + 1 x 0.32 =600 + 24 + 0.32 = 624.32

The amount at the end of 3 years = 5000 + 624.32 = 5624.32