Indian Institute of Foreign Trade 2015 Solved Paper

(b)
Using pythagoras theorem
Case (i) Height of wall $=\sqrt{{\left(7.6\right)}^2-{\left(6.4\right)}^2}$
$=\sqrt{\left(1.2\right)\times 14}$
$=\sqrt{16.8}$
$\approx 4.1$ m
When the ladder slips 1.2 m, its top edge would beat a height of 4.1 – 1.2 m ≈2.9 m

$\therefore \mathrm{BF}=\sqrt{{\left(7.6\right)}^2-{\left(2.9\right)}^2}\approx 7$
∴Ladder shifts approximately 7 – 6.4 = 0.6 m