Question

Determine if 2110 is divisible by 45​

Answer 1

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Let the age of father be x years

Let the age of one of his children be y years and age of other children be z years

From given information,

x=2×(y+z)...(1)

After 20 years,

(x+20)=(y+20)+(z+20)...(2)

Substituting value of (1) in (2), we get

2×(y+z) +20=y+z+40

2y+2z−y−z=40−20

y+z=20...(3)

Substituting value of (3) in (1), we get

x=2×(20)

⇒x=40

Answer 2

Answer:

Ex 3.5, 10 Determine if 25110 is divisible by 45. [Hint : 5 and 9 are co-prime numbers. Test the divisibility of the number by 5 and 9].