The average (arithmetic mean) amount of savings of ten students is Rs. 600. Three of the students have no savings at all and each of the others have at least Rs. 250 including Nihar, who has exactly Rs. 1300. The largest amount, in Rs., that any one student could have 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