Explanation

It is given that the six children were born at the interval of 2 years ,

Let consider their age as-

x years ( age of youngest child)

( x+2) years ( age of 2nd child)

(x+4) years ( age of 3rd child )

(x+6) years (age of 4 th child)

(x+8) years ( age of 5th child)

( x+10) years ( age of 6th child)

Given- the sum of ages of 6 children is 60

therefore according to the question :-

( x+x+2+x+4+x+6+x+8+x+10) = 60

6x + 30= 60

6x = 60-30=30

x = 30/ 6 = 5

∴ The age of youngest child is 5

Explanation

Clearly, from 1 to 100, there are ten numbers with 3 as the unit's digit- 3, 13, 23, 33, 43, 53, 63, 73, 83, 93;

and ten numbers with 3 as the ten's digit - 30, 31, 32, 33, 34, 35, 36, 37, 38, 39.

So, required number = 10 + 10 = 20.

Explanation

First, send 17 and 7.

After 7 minutes, 7 is at finish and 17 needs 10 more minutes to complete his travel. now send 13.

After 10 minutes 17 reaches finish and 13 needs 3 more minutes to complete. now send 3.

Both 3 and 13 reach the destination at the same time after 3 minutes.

hence the time taken is 7+10+3 = 20 minutes.

Explanation

Two trains each of length 150m are running in opposite directions at the same speed,

If they cross each other in 15 seconds,

36 is the speed of each train in Km per hour

Explanation

Let the number of buffaloes is x and the number of ducks is y. 

Each buffalo has 1 head & 4 legs.

Each duck has 1 head & 2 legs.

So the number of heads =x+y and the number of legs=4x+2y.

So, by the given condition,

4x+2y=2(x+y)+24

4x−2x+2y−2y=24

2x=24

x=12

ND-21-5-2023

Explanation

Original price of gift pack = Rs.80

Discount% = 15%

So, discount =

                  =

                 =12

So, discounted price = original price - Discount = 80-12=68

Hence The sale price is Rs.68

AGM 07.5.23

Explanation

Let the cost prices of the colour television sold at 30% profit and 40% profit be Rs. x and Rs. (35000 – x) respectively.

Total selling price of televisions = x + 30/100 x + (35000 – x) + 40/100 (35000 – x)

=> 130/100 x + 140/100 (35000 – x) = 35000 + 32/100 (35000)

x = 28000

35000 – x = 7000

Difference in the cost prices of televisions = Rs. 21000

Explanation

Let the amount lent at 7% be Rs. x

Amount lent at 10% is Rs. (6000 – x)

Total interest for one year on the two sums lent

= 7/100 x + 10/100 (6000 – x) = 600 – 3x/100

=> 600 – 3/100 x = 450 => x = 5000

Amount lent at 10% = 1000

Required ratio = 5000 : 1000 = 5 : 1

Explanation

Age of the 15th student=

[15 * 15 – (14 * 5 + 16 * 9)] = (225 – 214) = 11 years

Explanation

Let there be x pupils in the class.

Total increase in marks = (x * 1/2) = x/2

x/2 = (83 – 63) => x/2 = 20 => x = 40