Bank Exams Questions

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51 + 52 + 53 + ...........+ 100

 = (1 + 2 + 3 + .... + 100) - (1 + 2 + 3 + ...... + 50)

 = It is in the form of $\frac{n(n+1)}{2} series summation$

= n1 = 100 , n2 = 50

=$\left[\frac{{\displaystyle 100\left(100+1\right)}}{{\displaystyle 2}}\right] - \left[\frac{50\left(50+1\right)}{2}\right]$

 =  (5050 - 1275) = 3775

Time from 5 am. on a day to 10 pm. on 4th day = 89 hours.

Now 23 hrs 44 min. of this clock = 24 hours of correct clock.

356/15 hrs of this clock = 24 hours of correct clock

89 hrs of this clock = (24 x 31556 x 89) hrs of correct clock.

= 90 hrs of correct clock.

So, the correct time is 11 p.m.

let ABCD be the given parallelogram 

area of parallelogram ABCD = 2 x (area of triangle ABC) 

now a = 30m, b = 14m and c = 40m

 s=1/2 x (30+14+40) = 42 

Area of triangle ABC = $\sqrt{\left[s\left(s-a\right)\left(s-b\right)\left(s-c\right)\right]}$  

= $\sqrt{\left[42\left(12\right)\left(28\right)\left(2\right)\right]}$= 168sq m 

area of parallelogram ABCD = 2 x 168 = 336 sq m