Question

Total how many boys went to only the physics lab?

• A. 175
• B. 158
• C. 156
• D. 134
• E. None of these

Answer 1

The correct option is B 158


8:7 = 320 (boys) : 280 (girls)
$20\%both=20\times \frac{600}{100}=120$
$B-\left(phy\right)=40\times \frac{320}{100}=128$
$B-\left(both\right)=25\times \frac{120}{100}=30$
$G-\left(chem\right)=45\times \frac{280}{100}=126$
Total no of boys (phy) = 128 + 30 = 158