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A new queen size bed sheet

measures 210 cm by 240 cm.
The length and width each shrinks
by 2% after the first washing.
a) What are the dimensions of the
sheet after washing?
b) What is the percent decrease in
the area of the sheet?
Oh

User Feilong
by
5.4k points

1 Answer

6 votes

Answer:

a) The dimensions of the sheet after washing are 205.8 cm and 235.2 cm

b) The percent decrease in the area of the sheet is 3.96%

Explanation:

Let us solve the question

a)

∵ A new queen size bed sheet measures 210 cm by 240 cm.

∴ Length = 210 cm and width = 240 cm

∵ The length and width each shrinks by 2%

→ If the length is 100% and the width is 100%, they shrink by 2% each,

then the new length is 98% of the original length and the new width

is 98% of the original width

∴ The new length = 210 × 98% = 210 ×
(98)/(100) = 210 × 0.98

The new length = 205.8 cm

∴ The new width = 240 × 98% = 240 ×
(98)/(100) = 240 × 0.98

The new length = 235.2 cm

The dimensions of the sheet after washing are 205.8 cm and 235.2 cm

b)

∵ The area of the rectangle = length × width

∴ The area of the original sheet = 210 × 240 = 50400 cm²

∴ The area of the sheet after washing = 205.8 × 235.2 = 48404.16 cm²

→ Percent of decrease = (decrease ÷ original) × 100%

The decrease in area = 50400 - 48404.16 = 1995.84

∵ The original area = 50400

∴ The percent decrease = (1995.84 ÷ 50400) × 100%

∴ The percent decrease = 3.96%

The percent decrease in the area of the sheet is 3.96%

User Ousama
by
5.5k points