(Ram + Ravi)’s 1 day work = 1/15

(Ravi + Subhash)’s 1 day work = 1/20

(Ram + Subhash)’s 1 day work = 1/10

2( Ram + Ravi + subhash)’s 1 day work =1/15+ 1/20+ 1/10 = (4+3+6)/60 = 13/60

( Ram + Ravi + subhash)’s 1 day work =13/120

( Ram + Ravi + subhash) Can complete the work = 120/13 = 9 3/13

Let Marked Price = Rs.100

CP = 100 × 85/100 = Rs.85

Selling price at 20 % gain = 85 ×120/100 = Rs.102

Required ratio = MP/SP = 100/102 = 50/51

Dividend = divisor × quotient + Remainder

D = 357 × q + 47 = 17 × 21 × q + 17 × 2 + 13

So, (357 × q) and 17 × 2 both are divisible by 19. Remainder will be 13.

Let be length of train A is l so length of train b is l – 200.

Length of bridge is b.

Speed of train A = 90 × 5/18 = 25 m/sec

(l + b)/25 = 40

L + b = 1000

Speed of train A = 72 × 5/18 = 20 m/sec

Time taken by Train B to cross the bridge = (l – 200+b)/20

(1000-200)/20 = 800/20 = 40 sec

Let weight of 1 item = x kg

All are of same weight so 10 item weight = 10 x

ATQ, 10x + weight of empty drum = 15x

Weight of empty drum = 5x

5 items are taken out now Weight of drum = 5x + weight of empty drum

50 = 5x + 5x

10x = 50 → x = 10kg

Let cost of a book = Rs. 10

Cost of online test series = 10 + 10 × (200)/100 = 30

Initial cost of one book and one test series = 40

After 20% increase in cost price of a book CP = 10 × (120)/100 = 12

After 15 % increase in cost price of test series new CP = 30 × (115)/100 = 34.5

Total cost of one book and one test series = 12 + 34.5 = 46.5

Percentage increase = (46.5 – 40)/40 × 100 = (6.5)/40 × 100 = 65/4 = 16.25%

Let Average weight of girls = x kg

(x ×30 + 20 ×38)/50 = 36

x × 30 + 760 = 1800

x = 1040/30 = 34.66 kg

Difference = sum (r/100)^t

20.25 = sum (1/20)²

Sum = 20.25 × 20 × 20 = 8100