Question

In a party, one-fifth of the guests wanted cool drinks only. Out of the remaining, half of them liked coffee and two-thirds like tea. If 12 of the guests opted for both coffee and tea, how many guests had attended the party?

• A. 72
• B. 88
• C. 90
• D. 100

Answer 1

Answer:

C. 90

$\frac15=$cool drinks

rest is $\frac45$

$\frac45\times \frac12=\frac25=$coffee

rest is $\frac25$

$\frac25\times\frac23=\frac{4}{15}=$tea

rest is $\frac25\times \frac13=\frac{2}{15}$

this is the fraction of both tea and coffee

$\frac{2}{15}\times x=12$

$x=\frac{12\times 15}{2}=90$