Question

In design of a concrete mix by Fineness modulus method the value of F.M. of coarse aggregate is $7.3$, the value of fine aggregate is $2.8$, and value of F.M. of combined aggregates is $6.4$. The percentage of fine aggregate to combined aggregate is

• A. $25$
• B. $50$
• C. $75$
• D. $65$

Answer 1

The correct option is A $25$

The proportion of fine aggregate to combined aggregate -

$R=\frac{P_2-P}{P_2-P_1}\times 100$

$P_2=7.6,P=6.4,P_1=2.8$

$R=\frac{7.6-6.4}{7.6-2.8}\times 100$

$R=\frac{1.2}{4.8}\times 100$

$R=25\%$