Question

17. (4) Let third number ( =z )
( therefore ) First number ( =x=20 % ) of ( z )
[
=frac{20 times z}{100}=frac{z}{5}
]
and second number ( =y=50 % ) of ( z )
[
=frac{50 times z}{100}=frac{z}{2}
]
Hence, required percent ( =frac{z / 5}{z / 2} times 100 % )
[
=frac{2 times 100}{5} %=40 %
]

# 17. Two numbers are respectively 20% and 50% of a third number. What per cent is the first number of the second? (1) 10 (2) 20 (3) 30 (4) 40

Solution