Two trains of 200 m and 100 m long are running parallel at the rate of 20 m/sec. and 22 m/sec. respectively. How much time will they take to cross each other, if the trains are running along the same direction? [#1132]

The difference of speed = 22m/s - 20m/s = 2m/s As the train with speed 22m/s will cross the other, hence this train have to go the smallest length of the trains distance ahead of the other to cross completely. Hence This train will be ahead of 100m with a speed of 2m/s. Hence The time to cross each other will take = 100m / (2m/s) = 50 sec

---

The difference of speed = 22m/s - 20m/s = 2m/s As the train with speed 22m/s will cross the other, hence this train have to go the smallest length of the trains distance ahead of the other to cross completely. Hence This train will be ahead of 100m with a speed of 2m/s. Hence The time to cross each other will take = 100m / (2m/s) = 50 sec

720

---

720

An equilateral triangle is a triangle with three equal sides and angles, a regular polygon with three sides.

---

An equilateral triangle is a triangle with three equal sides and angles, a regular polygon with three sides.

In geometry, a vertex (plural: vertices) is the point where two or more lines, rays, or edges meet, like the corner of a triangle or the point where two streets intersect.

---

In geometry, a vertex (plural: vertices) is the point where two or more lines, rays, or edges meet, like the corner of a triangle or the point where two streets intersect.

1+3+5+7+9+11+13 = 49

---

1+3+5+7+9+11+13 = 49

16% decrease = 40-40-$\frac{40*40}{100}$% = -$\frac{1600}{100}$% = -16%

---

16% decrease = 40-40-$\frac{40*40}{100}$% = -$\frac{1600}{100}$% = -16%

6²-1 : 6 = 35 : 6 11²-1 : 11 = 120 : 11

---

6²-1 : 6 = 35 : 6 11²-1 : 11 = 120 : 11

25 years + (3*10) years = 55 years

---

25 years + (3*10) years = 55 years

47

---

47

A : B = 3 => $\frac{A}{B}$ = 3 $\frac{144A}{36B}$ = $\frac{144}{36}\times \frac{A}{B}$ = $\frac{144}{36}$ x 3 = 4 x 3 = 12

---

A : B = 3 => $\frac{A}{B}$ = 3 $\frac{144A}{36B}$ = $\frac{144}{36}\times \frac{A}{B}$ = $\frac{144}{36}$ x 3 = 4 x 3 = 12

41

---

41