{"id":3265,"date":"2026-10-31T06:19:46","date_gmt":"2026-10-31T06:19:46","guid":{"rendered":"https:\/\/tuyetky.com\/79\/?p=3265"},"modified":"2026-10-31T06:19:46","modified_gmt":"2026-10-31T06:19:46","slug":"vi-sao-giam-gia-50-roi-tang-50-lai-khong-ve-gia-cu","status":"publish","type":"post","link":"https:\/\/tuyetky.com\/79\/2026\/10\/31\/vi-sao-giam-gia-50-roi-tang-50-lai-khong-ve-gia-cu\/","title":{"rendered":"V\u00ec sao gi\u1ea3m gi\u00e1 50% r\u1ed3i t\u0103ng 50% l\u1ea1i kh\u00f4ng v\u1ec1 gi\u00e1 c\u0169?"},"content":{"rendered":"
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C\u1eeda h\u00e0ng treo bi\u1ec3n \u201cGi\u1ea3m 50%\u201d. V\u00e0i h\u00f4m sau h\u1ebft \u0111\u1ee3t khuy\u1ebfn m\u00e3i, h\u1ecd t\u0103ng gi\u00e1 l\u1ea1i 50% cho m\u1ecdi th\u1ee9. Nghe th\u00ec c\u00f3 v\u1ebb h\u1ee3p l\u00fd: gi\u1ea3m bao nhi\u00eau, t\u0103ng b\u1ea5y nhi\u00eau, gi\u00e1 ph\u1ea3i tr\u1edf v\u1ec1 ch\u1ed7 c\u0169 ch\u1ee9? Th\u1ef1c ra l\u00e0 kh\u00f4ng. V\u00e0 l\u00fd do n\u1eb1m \u1edf m\u1ed9t chi ti\u1ebft r\u1ea5t nh\u1ecf m\u00e0 ta hay b\u1ecf qua.<\/p>\n

Th\u1eed t\u00ednh v\u1edbi m\u1ed9t m\u00f3n \u0111\u1ed3 c\u1ee5 th\u1ec3<\/strong><\/p>\n

Gi\u1ea3 s\u1eed chi\u1ebfc \u00e1o \u0111ang c\u00f3 gi\u00e1 100.000 \u0111\u1ed3ng. Gi\u1ea3m 50% ngh\u0129a l\u00e0 b\u1edbt \u0111i m\u1ed9t n\u1eeda, c\u00f2n 50.000 \u0111\u1ed3ng. \u0110\u1ebfn l\u00fac t\u0103ng 50%, ta ph\u1ea3i h\u1ecfi: 50% c\u1ee7a c\u00e1i g\u00ec? C\u1ee7a gi\u00e1 hi\u1ec7n t\u1ea1i, t\u1ee9c 50.000 \u0111\u1ed3ng. M\u1ed9t n\u1eeda c\u1ee7a 50.000 l\u00e0 25.000, n\u00ean gi\u00e1 m\u1edbi ch\u1ec9 l\u00e0 75.000 \u0111\u1ed3ng, v\u1eabn th\u1ea5p h\u01a1n gi\u00e1 ban \u0111\u1ea7u 25.000 \u0111\u1ed3ng.<\/p>\n

\u0110i\u1ec3m m\u1ea5u ch\u1ed1t l\u00e0 ph\u1ea7n tr\u0103m lu\u00f4n \u0111\u01b0\u1ee3c t\u00ednh tr\u00ean m\u1ed9t \u201cm\u1ed1c\u201d n\u00e0o \u0111\u00f3. L\u1ea7n gi\u1ea3m l\u1ea5y m\u1ed1c l\u00e0 100.000 \u0111\u1ed3ng, l\u1ea7n t\u0103ng l\u1ea1i l\u1ea5y m\u1ed1c l\u00e0 50.000 \u0111\u1ed3ng. Hai m\u1ed1c kh\u00e1c nhau n\u00ean hai con s\u1ed1 50% kh\u00f4ng c\u00f2n ngh\u0129a l\u00e0 c\u00f9ng m\u1ed9t l\u01b0\u1ee3ng ti\u1ec1n.<\/p>\n

V\u00ec sao gi\u1ea3m nhi\u1ec1u th\u00ec c\u00e0ng kh\u00f3 \u201cg\u1ee1 l\u1ea1i\u201d?<\/strong><\/p>\n

N\u1ebfu g\u1ecdi m\u1ee9c gi\u1ea3m l\u00e0 x (vi\u1ebft d\u01b0\u1edbi d\u1ea1ng s\u1ed1 th\u1eadp ph\u00e2n) th\u00ec gi\u00e1 sau khi gi\u1ea3m l\u00e0 (1 \u2212 x) l\u1ea7n gi\u00e1 c\u0169. Mu\u1ed1n quay v\u1ec1 \u0111\u00fang gi\u00e1 c\u0169, ta c\u1ea7n nh\u00e2n th\u00eam m\u1ed9t s\u1ed1 sao cho t\u00edch b\u1eb1ng 1, t\u1ee9c l\u00e0 ph\u1ea3i t\u0103ng th\u00eam x chia cho (1 \u2212 x).<\/p>\n

\u0110\u1ecdc b\u1eb1ng l\u1eddi th\u00ec \u0111\u01a1n gi\u1ea3n h\u01a1n: gi\u1ea3m c\u00e0ng s\u00e2u, \u0111\u00e1y c\u00e0ng th\u1ea5p, v\u00e0 qu\u00e3ng \u0111\u01b0\u1eddng leo l\u00ean c\u00e0ng d\u00e0i so v\u1edbi ch\u00ednh c\u00e1i \u0111\u00e1y \u1ea5y. M\u1ed9t v\u00e0i con s\u1ed1 \u0111\u1ec3 d\u1ec5 h\u00ecnh dung:<\/p>\n

Gi\u1ea3m 10% th\u00ec c\u1ea7n t\u0103ng kho\u1ea3ng 11,1% m\u1edbi v\u1ec1 gi\u00e1 c\u0169. Gi\u1ea3m 20% th\u00ec c\u1ea7n t\u0103ng 25%. Gi\u1ea3m 50% th\u00ec c\u1ea7n t\u0103ng t\u1edbi 100%, ngh\u0129a l\u00e0 ph\u1ea3i g\u1ea5p \u0111\u00f4i. C\u00f2n n\u1ebfu gi\u1ea3m 90%, b\u1ea1n ph\u1ea3i t\u0103ng 900% m\u1edbi quay l\u1ea1i \u0111i\u1ec3m xu\u1ea5t ph\u00e1t.<\/p>\n

M\u1ed9t chi ti\u1ebft b\u1ea5t ng\u1edd: t\u0103ng r\u1ed3i gi\u1ea3m c\u0169ng kh\u00f4ng h\u00f2a<\/strong><\/p>\n

\u0110i\u1ec1u n\u00e0y \u0111\u00fang theo c\u1ea3 chi\u1ec1u ng\u01b0\u1ee3c l\u1ea1i. N\u1ebfu m\u1ed9t m\u00f3n h\u00e0ng 100.000 \u0111\u1ed3ng t\u0103ng 20% l\u00ean 120.000 \u0111\u1ed3ng, r\u1ed3i gi\u1ea3m 20%, b\u1ea1n s\u1ebd c\u00f3 96.000 \u0111\u1ed3ng ch\u1ee9 kh\u00f4ng ph\u1ea3i 100.000 \u0111\u1ed3ng. C\u1ee9 t\u0103ng x% r\u1ed3i gi\u1ea3m x%, k\u1ebft qu\u1ea3 lu\u00f4n th\u1ea5p h\u01a1n ban \u0111\u1ea7u \u0111\u00fang x\u00b2 ph\u1ea7n tr\u0103m c\u1ee7a gi\u00e1 g\u1ed1c. V\u1edbi 20%, \u0111\u00f3 l\u00e0 4%; v\u1edbi 10%, ch\u1ec9 l\u00e0 1%, n\u00ean ch\u00eanh l\u1ec7ch nh\u1ecf \u0111\u1ebfn m\u1ee9c ta th\u01b0\u1eddng kh\u00f4ng nh\u1eadn ra.<\/p>\n

Chuy\u1ec7n n\u00e0y c\u0169ng hay g\u1eb7p khi n\u00f3i v\u1ec1 l\u01b0\u01a1ng hay thu nh\u1eadp. N\u1ebfu l\u01b0\u01a1ng b\u1ecb c\u1eaft 20% trong m\u1ed9t giai \u0111o\u1ea1n kh\u00f3 kh\u0103n, th\u00ec sau \u0111\u00f3 ph\u1ea3i t\u0103ng 25% m\u1edbi tr\u1edf l\u1ea1i m\u1ee9c c\u0169. Ng\u01b0\u1eddi nghe th\u1ea5y \u201ct\u0103ng 20%\u201d c\u00f3 th\u1ec3 t\u01b0\u1edfng \u0111\u00e3 \u0111\u1ee7 b\u00f9, nh\u01b0ng th\u1eadt ra v\u1eabn c\u00f2n thi\u1ebfu m\u1ed9t ch\u00fat.<\/p>\n

C\u00f3 th\u1ec3 \u00e1p d\u1ee5ng g\u00ec trong \u0111\u1eddi s\u1ed1ng?<\/strong><\/p>\n

L\u1ea7n t\u1edbi th\u1ea5y nh\u1eefng d\u00f2ng nh\u01b0 \u201cgi\u1ea3m 30% r\u1ed3i gi\u1ea3m th\u00eam 20%\u201d, b\u1ea1n \u0111\u1eebng c\u1ed9ng th\u00e0nh 50%. V\u1edbi 100.000 \u0111\u1ed3ng, gi\u1ea3m 30% c\u00f2n 70.000 \u0111\u1ed3ng, gi\u1ea3m th\u00eam 20% c\u00f2n 56.000 \u0111\u1ed3ng, t\u1ee9c l\u00e0 t\u1ed5ng m\u1ee9c gi\u1ea3m l\u00e0 44%, kh\u00f4ng ph\u1ea3i 50%. C\u00e1ch t\u00ednh \u0111\u00fang l\u00e0 nh\u00e2n c\u00e1c h\u1ec7 s\u1ed1 l\u1ea1i v\u1edbi nhau: 0,7 \u00d7 0,8 = 0,56.<\/p>\n

Th\u00f3i quen \u0111\u01a1n gi\u1ea3n l\u00e0 lu\u00f4n t\u1ef1 h\u1ecfi \u201cph\u1ea7n tr\u0103m n\u00e0y t\u00ednh tr\u00ean con s\u1ed1 n\u00e0o?\u201d. Ch\u1ec9 c\u1ea7n h\u1ecfi nh\u01b0 v\u1eady, b\u1ea1n s\u1ebd \u00edt b\u1ecb nh\u1ea7m khi \u0111\u1ecdc b\u1ea3ng gi\u00e1, b\u1ea3ng l\u00e3i su\u1ea5t hay m\u1ed9t con s\u1ed1 t\u0103ng gi\u1ea3m trong b\u1ea3n tin. C\u00e1ch h\u1ecfi n\u00e0y c\u0169ng kh\u00f4ng c\u1ea7n \u0111\u1ebfn m\u00e1y t\u00ednh, ch\u1ec9 c\u1ea7n m\u1ed9t ph\u00e9p nh\u1ea9m v\u1edbi s\u1ed1 tr\u00f2n nh\u01b0 100.<\/p>\n

\u00dd ch\u00ednh c\u1ea7n nh\u1edb<\/strong><\/p>\n

Ph\u1ea7n tr\u0103m kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t l\u01b0\u1ee3ng c\u1ed1 \u0111\u1ecbnh, m\u00e0 lu\u00f4n l\u00e0 \u201cm\u1ed9t ph\u1ea7n c\u1ee7a c\u00e1i \u0111ang c\u00f3\u201d. V\u00ec th\u1ebf, gi\u1ea3m 50% r\u1ed3i t\u0103ng 50% kh\u00f4ng bao gi\u1edd \u0111\u01b0a ta v\u1ec1 ch\u1ed7 c\u0169; mu\u1ed1n v\u1ec1 ch\u1ed7 c\u0169 sau khi gi\u1ea3m m\u1ed9t n\u1eeda, ta ph\u1ea3i g\u1ea5p \u0111\u00f4i.<\/p>\n

TuyetKy.com ch\u00fac b\u1ea1n m\u1ed7i ng\u00e0y bi\u1ebft th\u00eam m\u1ed9t \u0111i\u1ec1u th\u00fa v\u1ecb!<\/p>\n

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C\u1eeda h\u00e0ng treo bi\u1ec3n \u201cGi\u1ea3m 50%\u201d. V\u00e0i h\u00f4m sau h\u1ebft \u0111\u1ee3t khuy\u1ebfn m\u00e3i, h\u1ecd t\u0103ng gi\u00e1 l\u1ea1i 50% cho m\u1ecdi th\u1ee9. Nghe th\u00ec c\u00f3 v\u1ebb h\u1ee3p l\u00fd: gi\u1ea3m bao nhi\u00eau, t\u0103ng b\u1ea5y nhi\u00eau, gi\u00e1 ph\u1ea3i tr\u1edf v\u1ec1 ch\u1ed7 c\u0169 ch\u1ee9? Th\u1ef1c ra l\u00e0 kh\u00f4ng. V\u00e0 l\u00fd do n\u1eb1m \u1edf m\u1ed9t chi ti\u1ebft r\u1ea5t nh\u1ecf m\u00e0...<\/p>\n","protected":false},"author":1,"featured_media":1817,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[87,82,487,489,488,125],"class_list":["post-3265","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-relax","tag-cuoc-song","tag-kien-thuc","tag-moi-ngay-mot-dieu-dang-biet","tag-mua-sam-thong-minh","tag-phan-tram","tag-tuyetky"],"jetpack_featured_media_url":"https:\/\/tuyetky.com\/79\/wp-content\/uploads\/2023\/06\/pexels-karolina-grabowska-4386473-scaled.jpg","_links":{"self":[{"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/posts\/3265","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/comments?post=3265"}],"version-history":[{"count":1,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/posts\/3265\/revisions"}],"predecessor-version":[{"id":3268,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/posts\/3265\/revisions\/3268"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/media\/1817"}],"wp:attachment":[{"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/media?parent=3265"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/categories?post=3265"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tuyetky.com\/79\/wp-json\/wp\/v2\/tags?post=3265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}