Ncert exemplar solutions mathematics class 8 Solutions for Chapter 9 comparing quantities

Suppose for the principal P, rate R% and time T, the simple interest is S and compound interest is C. Consider the possibilities.

(i) C > S

(ii) C = S

(iii) C < S

Then:

(a) only (i) is correct.

(b) either (i) or (ii) is correct.

(c) either (ii) or (iii) is correct.

(d) only (iii) is correct.

Suppose a certain sum doubles in 2 years at r % rate of simple interest per annum or at R% rate of interest per annum compounded annually. We have

(a) r < R

(b) R < r

(c) R = r

(d) can’t be decided

Both x and y vary inversely with each other. When x is 10, y is 6, which of the following is not a possible pair of corresponding values of x and y?

(a) 12 and 5

(b) 15 and 4

(c) 25 and 2.4

(d) 45 and 1.3

The compound interest on Rs 50,000 at 4% per annum for 2 years compounded annually is

(a)Rs 4,000 (b) Rs 4,080 (c) Rs 4,280 (d) Rs 4,050

If marked price of an article is Rs 1,200 and the discount is 12% then the selling price of the article is

(a) Rs 1,056 (b) Rs 1,344 (c) Rs 1,212 (d) Rs 1,188

If 90% of x is 315 km, then the value of x is

(a) 325 km (b) 350 km (c) 350 m (d) 325 m

To gain 25% after allowing a discount of 10%, the shopkeeper must mark the price of the article which costs him Rs 360 as

(a) Rs 500 (b) Rs 450 (c) Rs 460 (d) Rs 486

If a % is the discount per cent on a marked price x, then discount is

(a) (x/a) × 100

(b) (a/x) × 100

(c) x × (a/100)

(d) 100/(x × a)

Ashima took a loan of Rs 1,00,000 at 12% p.a. compounded half-yearly. She paid Rs.1,12,360. If (1.06)^2 is equal to 1.1236, then the period for which she took the loan is:

(a) 2 years (b) 1 year (c) 6 months (d) 1(1/2) years

For calculation of interest compounded half-yearly, keeping the principal same, which one of the following is true.

(a) Double the given annual rate and half the given number of years.

(b) Double the given annual rate as well as the given number of years.

(c) Half the given annual rate as well as the given number of years.

(d) Half the given annual rate and double the given number of years.

Latika bought a teapot for Rs 120 and a set of cups for Rs 400. She sold the teapot at a profit of 5% and cups at a loss of 5%. The amount received by her is:

(a) Rs 494 (b) Rs 546 (c) Rs 506 (d) Rs 534

A jacket was sold for Rs 1,120 after allowing a discount of 20%. The marked price of the jacket is:

(a) Rs 1440 (b) Rs 1400 (c) Rs 960 (d) Rs 866.66

A sum is taken for two years at 16% p.a. If interest is compounded after every three months, the number of times for which the interest is charged in 2 years is:

(a) 8 (b) 4 (c) 6 (d) 9

The original price of a washing machine which was bought for Rs 13,500 inclusive of 8% VAT is:

(a) Rs 12,420 (b) Rs 14,580 (c) Rs 12,500 (d) Rs 13,492

___ is a reduction on the marked price of the article.

Increase of a number from 150 to 162 is equal to increase of _______ per cent

15% increase in price of an article, which is Rs.1,620, is the increase of _______ .

Discount = _________

Discount = Discount % of___.

_________ is charged on the sale of an item by the government and is added to the bill amount.

Amount when interest is compounded annually is given by the formula_

Sales tax = tax % of _______

The time period after which the interest is added each time to form a new principal is called the ________

. _________ expenses are the additional expenses incurred by a buyer for an item over and above its cost of purchase.

The discount on an item for sale is calculated on the _______ .

When principal P is compounded semi-annually at r % per annum for t years, then Amount = ______

Percentages are equal to fractions with ________ equal to 100.

The marked price of an article when it is sold for Rs. 880 after a discount of 12% is ______

The compound interest on Rs 8,000 for one year at 16% p.a. compounded half yearly is__ , given that (1.08)^2 = 1.1664.

In the first year on an investment of Rs. 6,00,000 the loss is 5% and in the second year the gain is 10%, the net result is __________ .

If amount on the principal of Rs 6,000 is written as 6000 [1+5/100]^3 and compound interest payable half yearly, then rate of interest p.a. is ______ and time in years is _________ .

By selling an article for Rs 1,12,000 a girl gains 40%. The cost price of the article was ______ .

The loss per cent on selling 140 geometry boxes at the loss of S.P. of 10 geometry boxes is equal to _____

The cost price of 10 tables is equal to the sale price of 5 tables. The profit per cent in this transaction is ________ .

Abida bought 100 pens at the rate of Rs 3.50 per pen and pays a sales tax of 4%. The total amount paid by Abida is ________ .

The cost of a tape-recorder is Rs 10,800 inclusive of sales tax charged at 8%. The price of the tape-recorder before sales tax was charged is __________ .

2500 is greater than 500 by _________ .

Four times a number is a __________ increase in the number.

5% sales tax is charged on an article marked Rs 200 after allowing a discount of 5%, then the amount payable is ____

To calculate the growth of a bacteria if the rate of growth is known, the formula for calculation of amount in compound interest can be used.

Additional expenses made after buying an article are included in the cost price and are known as Value Added Tax.

Discount is a reduction given on cost price of an article.

Compound interest is the interest calculated on the previous year’s amount.

C.P. = M.P. – Discount.