Question

In a particular type of fertilizer, the ratio of two chemicals $A$ and $B$ is $2:5$. In $21kg$ of this fertilizer, if $3kg$ of $A$ is added. What will be the ratio of $A$ to $B$ in the new fertilizer?

• A. $1:1$
• B. $2:3$
• C. $3:5$
• D. $4:5$

Answer 1

The correct option is C $3:5$

Quantity of $A=\frac{2}{7}\times 21kg=6kg$,
Quantity of $B=\frac{5}{7}\times 21kg=15kg$
After adding $3kg$ of $A$ in the given fertilizer,

Required ratio $=\frac{QuantityofA}{QuantityofB}$

$=\frac{(6+3)kg}{15kg}=\frac{9}{15}=3:5$.