A few simpler questions

 

At the request of a few younger students I am going to post easier questions/problems. But we will always have a mix of easy and difficult items to meet the needs of different readers. Just do the ones you can, but at least read all postings.

Here are the problems for the coming week. Reply any time by writing in the comment field.

a)       Q1) 3*(2/3) - 2 *(3/4)  =  ?               

b)      Q2) What are the roots of the equation   x2-5x+6 = 0

c)       Q3) Sin(60 deg)2 +Cos(60 deg)2 = ?

d)      Q4) A vertical lamp post casts the sun’s shadow as long as its own height at a particular time, on a horizontal road. How many degrees above the road’s surface is the Sun at that moment?

e)      Q5) A boat travels an hour at 7 kmph up the river and at 5 kmph down the river till it reaches the starting point. How long would the return part of the journey take? The boat's speed is measured relative to the water.

Comments

Post a Comment

Popular posts from this blog

The trick Julius Caesar used to play

Image
Julius Caesar adopted a tricky method of sending messages to his generals through messengers. What if his enemies caught hold of the messenger and read the message? They will then know Caesar’s plans. Caesar’s trick was to change the letters in the message. For instance, he could write “D” instead of “A”, “E” instead of “B” and so on. Every letter would be replaced by another three places further down in the alphabetical order. What do you do with “Y”? What is three places beyond “Y”? The trick is to think of the letters being arranged in a ring so that “A” follows “Z” and “B” follows “A”. In this ring you can go three places from “Y” and find “B”. The letter three places ahead of “Z” will be “C”. To encipher a message, that is to make it secret, we first choose a key. I recommend that you choose a whole number between 1 and 6 as the key. Suppose you choose 3 as the key. Now replace every letter in “TEXT” by one which is 3 steps away along the ring. Do you get “WHAW”? You can send
Read more

You cannot win every time

Image
If you see the marks students get in a subject in your class, you will find that the largest number of people get average marks, while the number of those getting higher than the average gradually reduces. Similarly, the number of those getting less than average also reduces as you move away from the average. When teachers make a graph of the marks earned by the class, they get something that looks like this:                                                                     Image Credit: Monika Wahi,  CC-BY-SA-4.0 ,                                      Image from Wikimedia Commons In this example, we assume that D is the average score 50%. Other points are: A             20% B             30% C             40% E             60% F             70% G            80% The height above each letter shows how many people got that many marks: 2 students got 20%, 5 students got 30%, 7 students got 40%, 8 students got 50% 7 students got 60%, 5 students got 70%, and 2 students got
Read more

Cause and Effect

Image
  Cropped by Ramani. This file is licensed under the  Creative Commons   Attribution 3.0 Unported  license. Attribution:  Adeeb Atwan A fast motorbike went down our street one morning, making a big noise. Ten minutes later, my mom dropped her coffee mug. Can you say that the cause of mom dropping the coffee cup was the motorbike’s noise? Or was it a case of mere coincidence? This type of question was known long ago. An old Indian proverb talks about a crow and a palm tree. The crow came and sat on a palm tree and soon the tree fell down. Can we say that the crow’s sitting was the cause of the tree falling?    Or was it a case of mere coincidence? Srinivasan Ramani  
Read more