Question

Mark is four years younger than his brother. Their sister's age is half of their combined age. If the combined age of all 3 people is 138, how old is each person? SHOW WORk

Answer 1

$\huge\mathtt\orange{Hey!}$

$\large\purple{\sf{QUESTION}}$

ᴍᴀʀᴋ ɪs ғᴏᴜʀ ʏᴇᴀʀs ʏᴏᴜɴɢᴇʀ ᴛʜᴀɴ ʜɪs ʙʀᴏᴛʜᴇʀ. ᴛʜᴇɪʀ sɪsᴛᴇʀ's ᴀɢᴇ ɪs ʜᴀʟғ ᴏғ ᴛʜᴇɪʀ ᴄᴏᴍʙɪɴᴇᴅ ᴀɢᴇ. ɪғ ᴛʜᴇ ᴄᴏᴍʙɪɴᴇᴅ ᴀɢᴇ ᴏғ ᴀʟʟ 3 ᴘᴇᴏᴘʟᴇ ɪs 138, ʜᴏᴡ ᴏʟᴅ ɪs ᴇᴀᴄʜ ᴘᴇʀsᴏɴ?

$\large\blue{\sf{SOLUTION}}$

$\large{\sf{Combined~age=138}}$

$\large{\sf{Sister's~age= \frac{138}{2} }}$

$\large{\sf{Hence~sister's~age=69}}$

$\large{\sf{Let~the~age~of~Mark's~brother~be~x}}$

$\large{\sf{So,~Mark's~age=x-4}}$

$\large{\sf{We~can~say-}}$

$\large{\sf{x~-~4~+~x~+~69=138}}$

$\large{\sf{2x~+~65=138}}$

$\large{\sf{2x~=138-65}}$

$\large{\sf{2x~=73}}$

$\large{\sf{x~= \frac{73}{2} }}$

$\large{\sf{x~=36.5}}$

$\large\underline\green{\sf{.°. Age~of~Mark=32.5}}$

$\large\underline\pink{\sf{Age~of~Mark's~brother=36.5}}$

$\large\underline\blue{\sf{Age~of~Mark's~sister=69}}$

I think u have written qu. wrong cuz age is mostly not in decimal :) but hope it gonna help u