During the first year, the strength of a school increased by 12%, in the second year it decreased by 12% and in the third year it increased by 10%. At the end of the third year its strength was nearly 10842. What was the strength at the beginning of the first year? 

10000

Let initial strength = X

ATQ ,

X × \(\frac{112}{100}\) × \(\frac{88}{100}\) × \(\frac{110}{100}\) = 10842

X × \(\frac{28}{25}\) × \(\frac{22}{25}\) × \(\frac{22}{20}\) = 10842

X = 10000 (approx)