Quantitative Aptitude - Arithmetic Ability Questions

Given lb =96

Area of pathway = [(l-4)(b-4)-lb] = 16-4(l+b)

Which cannot be determined. so, data is inadequate.

Total ages of 80 boys = 15 x 80 = 1200 yrs.
Total age of 16 boys = 15 x 16 = 240 yrs
Total age of 25 boys = 14 x 25 = 350 yrs.
Average age of remaining boys = 1200 - (240+350) / 80 - (25+15) = 610/41 = 15.25 yrs.

NOTE: When a century year leaves a remiander 0, when divided by 400 then it is a leap year (366 days).

So, 1200 has 366 days.

To find the greatest number which divides the numbers 964, 1238 and 1400 leaving the remainders 41, 31 and 51 is nothing but the HCF of (964 - 41), (1238 - 31), (1400 - 51).

Therefore, HCF of 923, 1207 and 1349 is 71.

Probability that only one of them is selected = (prob. that brother is selected) × (prob. that sister is not selected) +  (Prob. that brother is not selected) × (Prob. that sister is selected)

= 15*23+45*13= 25

The hour hand moves from pointing to 12 to pointing to half way between 2 and 3. The angle covered between each hour marking on the clock is 360/12 = 30. Since the hand has covered 2.5 of these divisions the angle moved through is 75.

Let us name the trains as A and B.

Then, (A's speed) : (B's speed)

= √b : √a = √16 : √9 = 4:3

Let the three parts be A, B, C. Then,

A : B = 2 : 3 and B : C = 5 : 8 =5*35:8*35=  3:245  

A : B : C = 2 : 3 : =>  = 10 : 15 : 24

 B =245 = 30