All MCQs

Let cost be 100; marked price is 125 and sale price is 90% of 125 = 112.5.
The profit is 12.5 on a cost of 100.

After a 10% discount, 90% remains; after another 20%, 80% of that remains.
The final price is 72%, so the total discount is 28%.

The discount is 15% of Rs. 2,000, which is Rs. 300.
The sale price is Rs. 2,000 - Rs. 300 = Rs. 1,700.

The selling price is 125% of the cost price.
Thus, cost price = 1,500 ÷ 1.25 = Rs. 1,200.

A 10% loss on Rs. 1,200 is Rs. 120.
Subtracting gives a selling price of Rs. 1,080.

Profit equals selling price minus cost price.
Thus, 920 - 800 = Rs. 120.

Let the numbers be 5k and 8k; then (5k + 9)/(8k + 9) = 2/3.
Solving gives k = 9, so the smaller number is 45.

Initially, milk is 42 liters and water is 18 liters.
For a 7:5 ratio with 42 liters milk, water must be 30 liters, so add 12.

The difference between C and A is 2 ratio parts, equal to Rs. 600.
One part is Rs. 300, so 12 parts total Rs. 3,600.

The average of 1 through n is (n + 1)/2.
Setting (n + 1)/2 = 20 gives n = 39.

Six consecutive integers centered at 17.5 are 15 through 20.
Therefore, the smallest is 15.

Five parts equal Rs. 50,000, so one part is Rs. 10,000.
Expenditure is four parts, leaving one part as saving.