In a room of 100 people, 99% are left-handed. How many left-handed people have to leave the room to bring that percentage down to 98%?

Question

Bright Tutorials · Accepted Answer

No. of people in room = 100
No. of left handers = 99% of 100 = 99
No. of right-handers = 1
Let x people leave.
No. of left-handers is 98%.
and no. of right-handers is 2%.
Then $\frac{99-x}{100-x}=\frac{98}{100}$
⇒ 100(99 – x) = 98(100 – x)
⇒ 9900 – 100x = 9800 – 98x
⇒ 9900 – 9800 = 100x – 98x
⇒ 2x = 100
⇒ x = 50
∴ 50 left-handers must leave the room.

Fractions in Disguise — Question 14