Percentage - Study Mode
[#321] Out of his total income, Mr. Kapur spends 20% on house rent and 70% of the rest on house hold expenses. If he saves Rs. 1800 what is his total income (in Rs.) ?
Correct Answer
(D) Rs. 7500
Explanation
Solution: Let Mr.kapur income is 100x House rent 20%, i.e. 20x Remaining income 100x - 20x = 80x Now 70% of his remaining income spend in house hold expenses i.e. 70% of 80x = 56x Remain saving is 80x - 56x = 24x According to question 24x = 1800 x = $$frac{{1800}}{{24}} = 75$$ Mr.kapur income = 100 × 75 = 7500
[#322] Two numbers are in the ratio 2 : 3. If 20% of the smaller number added to 20, is equal to the sum of 10% of the larger number and 25, the the smaller number is :
Correct Answer
(A) 100
Explanation
Solution: Let the numbers are 2x and 3x respectively According to the question, 2x × $$frac{20}{100}$$ + 20 = 3x × $$frac{10}{100}$$ + 25 $$frac{2}{5}$$x + 20 = $$frac{3}{10}$$ + 25 $$frac{3}{10}$$x - $$frac{2}{5}$$x = - 5 3x - 4x = - 50 x = 50 Hence, required smaller number = 2x = 2 × 50 = 100
[#323] x * 12 = 75% of 336 Find x.
Correct Answer
(C) 21
Explanation
Solution: $$eqalign{
& 12x = frac{{ {75 imes 336} }}{{100}} cr
& x = frac{{ {75 imes 336} }}{{ {100 imes 12} }} cr
& x = 21 cr} $$
[#324] A shop sells floor tiles at Rs. 48 per square meter. A contractor employs a machine that polishes the tiles that damages 10% of the total number of tiles which cannot be used any more. Calculate the amount that needs to be paid by contractor to tile shop owner, if the hall is of a square shape and has a perimeter of 400 meters?
Correct Answer
(C) Rs. 5,28,000
Explanation
Solution: Let the side of the square shaped hall be X meter
Then, Perimeter = 4X 4X = 400 X = 100m Area of the hall = 100 × 100 = 10000 sq. meter. Now, The cost on total tiles = 10000 × 48 = Rs. 480000 But, 10% damage has occurred on tiles which will also be included in cost i.e Total cost = 480000 + 10% of 480000 = 480000 + 48000
Total cost = Rs. 5,28,000
[#325] 125% of 860 + 75% of 480 = ?
Correct Answer
(C) 1435
Explanation
Solution: $$eqalign{
& { {frac{{ {125 imes 860} }}{{100}}} + {frac{{75 imes 480}}{{100}}} } cr
& = 1075 + 360 cr
& = 1435 cr} $$