The average age of Hari, his wife and their two children is 23 years. His wife is just 4 years younger than Hari and his wife was 20 years old when their daughter was born. He was 28 years old when their son was born. What is the sum of the age of Hari and his daughter is?

If A runs 600 m, B runs 600 - 60 or, 540 m.
If A runs 400 m, B runs = 540 x 400 / 600 = 360 m.
Now, when B runs 500 m, C runs 500 - 50 = 450 m.
? When B runs 360 m, C runs = 450 * 360 / 500 = 324 m
? A beats C by 400 - 324 = 76 m.

Let Y = 0.15 / (0.5 / 15)
= (15/100) / [(5/100) / 15)
= 4.5

Putting arbitrary values of a and b.

IIIustration 1:
Let a = 9 and b = 8
HCF (8 + 9, 9 - 8)
HCF (17, 1) = 1

IIIustration 2:
Let a = 23 and b =17
HCF (17 + 23, 23 -17)
HCF ( 40, 6) = 2

Hence, HCF (a + b, a - b) can either be 1 or 2.

2079 is divisible by each of 3, 7, 9, 11.

Monthly sale = yearly sale / 2
= 132000 / 2
= ? 11000

June's sale = monthly sale / 2
= 11000 / 2
= ? 1000

Given that 0.8 x A = 0.09 x B
? A/B = 0.09/0.8 = 9/80
? A : B = 9 :80

For an income of Rs. 5, investment = Rs. 100
For an income of Rs. 4, investment = Rs. (100/5) x 4 = Rs. 80

For the product of 3.5413 x 2.1
Consider 35413 x 21 = 743673
Total decimal places = 4 + 1
? 3.5413 x 2.1=7.43673

? In 2/3h, 1 article is made.
? In 1h, 3/2 article are made.
? In 7¹/₂ = 15/2h, 3/2 x 15/2 = 45/4 article are made.
? Required articles = 45/4 = 11²/₄