Question 1

40% of 75 + 80% of 25 = K% of 250 Find the value of K?

Accepted Answer

From the given data, 40 100 x 75 + 80 100 x 25 = K 100 x 250 30 + 20 = 5 K 2 50 x 2 = 5 K K = 100 5 = 20

Question 2

20% of 120?

Accepted Answer

20% of 120 20 x 120/100 = 4 x 6 = 24 Hence, 20% of 120 = 24.

Question 3

What is 6% of 3,50,000?

Accepted Answer

6% of 350000 6 100 x 3 , 50 , 000 = 6 x 3500 = 21 , 000 . Hence, 6% of 3,50,000 = 21,000.

Question 4

The percentage of metals in a mine of zinc ore is 60%. Now the percentage of silver is 3/4% of metals and the rest is zinc. If the mass of ore extracted from the mine is 8000 kg, the mass (in kg) of zinc is

Accepted Answer

Mass of zinc ore = 8000 kg Mass of metal = 60% of 8000 = 4800 kg Mass of silver in metal = 3/4 x 4800/100 = 36 kg Mass of zinc = 4800 - 36 = 4764 kg.

Question 5

21 is 35 of what number?

Accepted Answer

The given sentence 21 is 35 of what number means that 21 is 35 % of what number Let that number be P => 35P/100 = 21 35P = 2100 P = 2100/35 = 300/5 = 60 Hence, 21 is 35 of 60.

Question 6

x, y and z are three numbers such that x is 30% of z and y is 40% of z. If x is p% of y, then what is the value of p?

Accepted Answer

x = 30% of z = 30z/100 = 3z/10 y = 40% of z = 40z/100 = 4z/10 According to the question,(x/y)*100 = p% p% = 3z/100/4z/100×100= 75%

Question 7

In a hostel the rent per room is increased by 20%. If number of rooms in the hostel is also increased by 20% and the hostel is always full, then what is the percentage change in the total collection at the cash counter?

Accepted Answer

Let initial rent be rs 10 And initial rooms be 10 So initial collection = 10*10 = Rs 100 Now new rent = 10 + 20% of 10 = 12 New no of rooms = 10 + 20% of 10 = 12 So new collection = 12*12 = 144 % change in collection = (144-100)/100*100 = 44%

Percentage Questions