Question

a) The dierence between decreasing a number by 7% and increasing it by 8% is 75. Find thenumber.

b)Sohail’s income is 25% more than that of Rachna’s income. What percent is Rachna’sincome less than Sohail’s income?

c) A sum of ` 3500 is divided between three friends such that first friend gets 50% of whatsecond friend get. Second friend gets 50% of what third friend get. Find the share of each friend.

d) Shamita got 80% marks in a Math test which had 20 problems. How many problems on thistest did she answer correctly? (round o to the nearest whole number)

Answer 1

Answer:

a. the number is 500.

b. 20%

c. first friend - 500, second friend - 1000, third friend - 2000

d. 16

Step-by-step explanation:

a. assuming the number is x.

increasing the no by 8% will give you 1.08x

decreasing the no by 7% will give you 0.93x

therefore, 1.08x - 0.93x = 75

which gives us x=500

b. assuming rachna's salary is ₹100.

therefore, sohail's salaray = 100 + 25%(100) = 125.

to find what percent rachna's income is less than sohail's ----- (125-100)/125 * 100 = 20%

c. assuming second friend gets 2x. therefore first friend gets x and third friend gets 4x.

therefore, x + 2x + 4x = 3500.

which gives you x = 500.

therefore first friend gets 500, second gets 1000 and third gets 2000.

d. assuming that all questions have same marks alloted,

Shamita answered 80% of the 20 questions to obtain80% marks.

80% of 20 = 16. therefore she answered 16 questions correctly.