# Exercise 1

(b) 2850000

(c) 2121000

(d) 1855000

(e) None of these

**Ans.e**

Let income in 1997 = x

According to the question,

Income in 1998 = x + ^{x}⁄_{5} = ^{6x}⁄_{5}

Income in 1999 = ^{6x}⁄_{5} + ^{6x}⁄_{25} = ^{36x}⁄_{25}

But given, income in 1999 = 2664000

∴ ^{36x}⁄_{25} = 2664000 ⇒ x = 1850000

(b) 75%

(c) 200%

(d) 100%

(e) None of these

**Ans.d**

Percentage growth from 1994 to 1996

= +25 + 60 + \(\frac{25 \times 60}{100}\) = +100%

(b) 415000

(c) 31500

(d) 50000

(e) None of these

**Ans.a**

Servant’s commission amount

= 6000 – 1500 = 4500

i.e.,15% = 4500

or,100% = ^{4500}⁄_{15} × 100 = 30000

(b) 8076

(c) 9691.20

(d) 4845.60

(e) None of these

**Ans.a**

∵ Amount, he have spent in 1 month on clothes transport = Amount spent on saving per month

∵ Amount, spent on clothes and transport

= ^{48456}⁄_{12} = ₹4038

(b) 36

(c) 30

(d) 48

(e) None of these

**Ans.a**

Number of students who speak only English

= 30% of 60 = 18

∵ Number of students who speak Hindi and English

= 20% of 60 = 12

∵ Number of students who speak only Hindi

= (60 – 30 =) 30

∵ No. of students who speak Hindi = 30 + 12 = 42

(b) 11%

(c) 20%

(d) 17%

(e) None of these

**Ans.d**

**Quicker Method:**

% profit which Somesh gets

= –10 +30 – \(\frac{10 \times 30}{100}\) = +17%

(b) 1998

(c) 1999

(d) 2000

(e) None of these

**Ans.b**

Suppose in ‘n’ years the price of comodity X will be more by 40 paise than that of commodity Y.

∴ 420 + 40n – 630 – 15n = 40

or, 25n – 210 = 40

or, 25n = 250

or, n = ^{250}⁄_{25} = 10 years.

(b) 100500

(c) 105000

(d) Data inadequate

(e) None of these

**Ans.c**

Let the investment of X in 1995 be ₹x.

∴ Profit = ₹ ^{x}⁄_{5}

∴ Income = ₹ (x + ^{x}⁄_{5}) = ₹ ^{6}⁄_{5}x

Investment of company X in 1996 would be (x – 5000) From the question,

(x - 500) × ^{126}⁄_{100} = ^{6}⁄_{5}x ⇒ x = ₹ 105000

(b) Decrease approximately by 2%

(c) Increase approximately by 20%

(d) Decrease approximately by 20%

(e) None of these

**Ans.e**

Let the strength of school was x in 1998

∴ strength in 2001 will be

= x^{110}⁄_{100} × ^{90}⁄_{100} × ^{110}⁄_{100} × ^{90}⁄_{100} × ^{110}⁄_{100} = 1.07811 x

increment = 1.07811 x – x = 0.07811 x

∴ % increase = 7.811 ≈ 8%

(b) 7 litres

(c) 15 litres

(d) Cannot be determined

(e) None of these

**Ans.c**

Here required quantity of pure milk = \(\frac{10 \times \left( 5 - 2\right)}{2}\)

= \(\frac{10 \times 3}{2}\) = 15 litres.