Question

(4) Four years ago, Rahim's age was three times Ramu's age. After two years, it would just be double. What are their ages now?​

Answer 1

Answer:

The paper is initially attracted to the comb because the comb causes separation of charge in the paper. The part of the paper pieces with positive charge is attracted to the comb. When the paper touches the comb, some of the excess negative charge in the comb is transferred to the paper.

Answer 2

Solution :

$\large \sf \: let \: \:p resent \: \: ages \: \: of :$

• Rahim = x years

• Ramu = y years

Now,

$\large \sf \: \: \: \: \: \: \star \: \: 4 \: \: years \: \: ago :$

$\large \implies \rm \: age \: \: of \: \: rahim = (x - 4)years \\ \\ \large \implies \rm \: age \: \: of \: \: rahim = (y - 4)years$

Given :

• 4 years ago :

☆ Rahim's age was three times Ramu's age..

$\\ \large \sf \implies \: (x - 4) = 3(y - 4) \\ \\ \large \sf \implies \: x - 4 = 3y - 12 \\ \\ \large \sf \implies \: x - 3y = - 12 + 4\\ \\ \large \tt \therefore \: \: x - 3y = - 8 \longrightarrow (1)$

$\large \star \: \rm \: after \: \: 2 \: \: years :$

$\large \rm \implies \: (x + 2) = 2(y + 2) \\ \\ \large \rm \implies \: x + 2 = 2y + 4 \\ \\ \large \rm \implies \: x - 2y = 4 - 2 \\ \\ \large \tt \therefore \: \: x - 2y = 2 \longrightarrow(2)$

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▪︎ On Solving (1) and (2) :

$\large \implies \rm \: x - 3y = - 8 \\ \large \rm \: \: \: \: \: \: \: \: \: x - 2y = 2 \\ \: \: \: - \: \:\: \: \: \: \: \: \: + \: \: \: \: \: \: \: + \\ \large \rm \: \: \: \: \: \: \: \: \: \: \underline{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: } \\ \large \rm \implies \: - y = - 10$

$\large \sf \therefore \: y = 10$

• Substituting value of 'y' in (1) :

$\\ \large \implies \rm \: x - 3y = - 8 \\ \\ \large \implies \rm \: x - 3(10) = - 8 \\ \\ \large \implies \rm \: x - 30 = - 8 \\ \\ \large \rm \implies \: x = - 8 + 30 \\ \\ \large \sf \therefore \: \: x = 22$

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Therefore,

$\\ \large \sf \star\: \:p resent \: \: ages \: \: of :$

• Rahim = 22 years

• Ramu = 10 years