# Tricks and Tips for Boat and Stream type Questions

## Tricks and Tips for Boat and Stream type Questions

Shortcut tricks on boats and streams are one of the most important topics in exams. These are the formulas and examples on Boats and Streams (Cyclist and the wind or Swimmer and stream) questions. These examples will help you to better understand shortcut tricks on boats and streams questions.

#### There are multiple types of questions asked from these topics.

• The speed of the boat in still water and the speed of stream will give in questions, You have to find the time taken by boat to go upstream and downstream.
• The speed of the boat in up and down stream will give in question,  you need to find the average speed of the boat.
• The speed of boat to go up or down the stream will give in question, you need to find speed of boat in still water and speed of stream
• The time taken by boat to reach a place in up and downstream will given in question, you need to find the distance to the place

#### Basic Formulas

• In water, the direction along with stream is called Downstream.
• The direction of the boat against the stream is called Upstream.
• The speed of boat or man in calm water which we denoted by sb.
• The speed of water or stream that denoted by sw
• Speed of boat in downstream (along the river) =  (sb + sw)
• Speed of boat in upstream (against the river) = (sb - sw)
• Speed of boat in still water ss = ½(sb + sw)
• Speed of water current (Rate of stream) sc = ½(sb – sw)

#### Sample Questions

1. A man can row 18km/hr in still water. the speed of the man in downstream is thrice the speed in upstream. Find the rate of the stream?.

Let assume, Speed of man in upstream = x

Speed of man in downstream = 3x

Speed of man in still water ss = ½( x + 3x)

= 2x

We know speed of man in still water = 18

ie,  x = 9

Rate of stream = ½(27 – 9) =9 km/hr.

Science Subjects Memory Code

കുലീന ലോഹങ്ങള്‍ .

Code: വെള്ളിയാഴ്ച സുവര്‍ണ്ണ ഫ്‌ളാറ്റില്‍ വരും (വെള്ളി, സ്വര്‍ണ്ണം, പ്ലാറ്റിനം).
ദ്രാവകാവസ്ഥയിലുള്ള ലോഹങ്ങള്‍ .

Code: MG ഫ്രാന്‍സിസ്‌ (മെര്‍ക്കുറി, ഗാലിയം, ഫ്രാന്‍സിയം, സീസിയം).
ഭൂമിയില്‍, പ്രപഞ്ചത്തില്‍, അന്തരീക്ഷത്തില്‍ ഏറ്റവും കുടുതലുള്ള മൂലകങ്ങള്‍ .

Code: BO PH AN (B - ഭൂമിയില്‍ O -ഓക്‌സിജന്‍, P - പ്രപഞ്ചത്തില്‍ H -ഹൈഡ്രജന്‍, A - അന്തരീക്ഷത്തില്‍ N -ന...

ഗണിത സൂത്രവാക്യം

ആദ്യത്തെ \'n\' എണ്ണൽ സംഖ്യകളുടെ തുക = n(n+1) /2.
ആദ്യത്തെ \'n\' ഒറ്റ സംഖ്യകളുടെ തുക = n².
ആദ്യത്തെ \'n\' ഇരട്ട സംഖ്യകളുടെ തുക = n(n+1).
ആദ്യത്തെ \'n\' എണ്ണൽ സംഖ്യകളുടെ വർഗ്ഗങ്ങളുടെ തുക = n(n+1)(2n+1) / 6.
ആദ്യത്തെ \'n\' എണ്ണൽ സംഖ്യകളുടെ ക്യൂബുകളുടെ തുക = [n(n+1)/ 2]².
ആദ്യ പദം \'a\', പൊതു വ്യത്യാസം \'d\' ആയാൽ n-മത്തെ പദം കാണാൻ = a+ (n -1) d.
ആദ്യ പദം \'a\', പൊതു വ്യത്യാസം \'d\' ആയാൽ, n പദങ്ങളുടെ തുക കാണാൻ = n/2[2a + (n - 1)d].
ആദ്യ പദവും (t1), n...

Divisibility Rule

What is the divisibility by 2 Rule?.
Even numbers are multiples of 2. A number is even if ends in 0,2,4,6, or 8.
What is the divisibility by 3 rule?.
A number is divisible by 3 if the sum of its digits is divisible by 3.
372, for instance, is divisible by 3 since sum of its digits (3+7+2) is 12. And 12 is divisible by 3.
What is the divisibility by 4 rule?.
A number is divisible by 4 if the number\'s  last two digits are divisible by 4.
9,312, for instance, is divisible by 4 since its last 2 digits are 12. And 12 is divisible by 4.
What is the divisibility by 5 rule?.
A number is divisible by 5 if its last digit is a 0 or 5.
What is the divisibility by 6 rule?.
Since 6 is a multiple of 2 and 3, the rules for divisibility by 6 are a combination of the rule for 2 and the rule for   3.
Divisibility by 8 Rule.
A number passes the test for 8 if the las...