40% of (100 – 20% of 300)

40% of (100 - 60) ---> 16

By equating the powers;

3 – 6 = 2x – 1

2x = - 2

x = -1

A can do a piece of work in 15 days and B can do it 22½ days.

Hence, Total work = 45 unit

Efficiency of A = 3 unit

Efficiency of B = 2 unit

A and B worked together for 6 days.

Let the present age of Rahul=3x

Let the present age of his sister=4x

As per questions

57x-190=52x-130

5x=60

X=12

Rahul present age=3x=36

Simple Interest for 2 years = Rs. (870 - 724) = Rs. 146

So, the Interest for 4 years = 146×2 = Rs. 292

Principal = Amount - Interest

=(724 - 292 ) = Rs. 432

By increasing speed by 2 km/hour the time reduced by 1 hour.

10 × 6 = 60 and 12 × 5 = 60

10 new speed

12 old speed

5 old time

6 new time

CP= ₹1500 and gain%= 15%

∴ SP = CP(100+gain)/100 ⇒ SP = 1500×(100+15)/100 = ₹1725

Since, SP= MP (100-d)/100; where d= %discount

⇒ 1725= MP (100-25)/100

⇒ MP =172500/75 = ₹2300

Mean of 20 number = 40

Sum of numbers = 40 × 20

= 800

According to question

10 is subtracted from each number then the total sum subtracted

= 10 × 20

= 200

New sum = 800 - 200

= 600

Ratio of incomes of A and B is 3 : 8

Let income of A = 3x

Income of B = 8x

Also, Ratio of savings of A and B is 9 : 25

Saving of A = 9y

Saving of B = 25y

⇒ Expenditure = Income - Saving

Expenditure of A = 3x-9y…………..(1)

Expenditure of B = 8x-25y…………..(2)

If the income of A equals the expenditure of B then

3x = 8x – 25y

⇒ 25y = 5x

⇒ x= 5y …………(3)

Expenditure of A = 3x-9y = 6y………………(4)

Expenditure of B = 8x-25y = 15y……………..(5)

Ratio of expenditure of A and B = 6y:15y = 2:5

Hence, the required answer is 25