Question

The number a is smaller than the number b by 1/5 of b. By what part of a is b bigger than a?

Answer 1

Answer:

The number b is bigger than the number a by $\dfrac{1}{4}$ of a.

Step-by-step explanation:

1. If the number a is smaller than the number b by 1/5 of b, then

$a+\dfrac{1}{5}b=b.$

Thus,

$a=b-\dfrac{1}{5}b=\dfrac{4}{5}b,\\ \\b=\dfrac{5}{4}a.$

2. Consider the expression $b=\dfrac{5}{4}a:$

$b=\dfrac{5}{4}a=\dfrac{4}{4}a+\dfrac{1}{4}a=a+\dfrac{1}{4}a.$

This gives you that the number b is bigger than the number a by $\dfrac{1}{4}$ of a.