A boat covers a certain distance upstream in 15 hours and covers the same distance downstream in 9 hours. The boat covers x km in still water in 5 hours and also covers (x + 30) km downstream in 5 hours. Find the speed of the boat in still water.<\/p>\n\n\n\n
a) 18 km\/hr<\/p>\n\n\n\n
b) 20 km\/hr<\/p>\n\n\n\n
c) 30 km\/hr<\/p>\n\n\n\n
d) 24 km\/hr<\/strong><\/p>\n\n\n\n e) None of these<\/p>\n\n\n\n Sol:<\/p>\n\n\n\n Speed of the boat in still water = B km\/hr<\/p>\n\n\n\n Speed of the current = C km\/hr<\/p>\n\n\n\n (B + C) * 9 = (B \u2013 C) * 15<\/p>\n\n\n\n 9B + 9C = 15B \u2013 15C<\/p>\n\n\n\n 6B = 24C<\/p>\n\n\n\n B\/C = 4\/1<\/p>\n\n\n\n Speed of the boat in still water = 4y km\/hr<\/p>\n\n\n\n Speed of the current = y km\/hr<\/p>\n\n\n\n x\/4y = 5<\/p>\n\n\n\n x = 20y<\/p>\n\n\n\n (x + 30)\/(4y + y) = 5<\/p>\n\n\n\n (20y + 30)\/5y = 5<\/p>\n\n\n\n 20y + 30 = 25y<\/p>\n\n\n\n 5y = 30<\/p>\n\n\n\n y = 6 km\/hr<\/p>\n\n\n\n Speed of the boat in still water = 4 * 6 = 24 km\/hr<\/p>\n","protected":false},"excerpt":{"rendered":" A boat covers a certain distance upstream in 15 hours and covers the same distance downstream in 9 hours. The boat covers x km in still water in 5 hours and also covers (x + 30) km downstream in 5 hours. Find the speed of the boat in still water. a) 18 km\/hr b) 20 […]<\/p>\n","protected":false},"author":419,"featured_media":163312,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[5138],"tags":[5139],"class_list":["post-163311","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-quantitative-aptitude","tag-quantitative-aptitude"],"_links":{"self":[{"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/posts\/163311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/users\/419"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/comments?post=163311"}],"version-history":[{"count":1,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/posts\/163311\/revisions"}],"predecessor-version":[{"id":163313,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/posts\/163311\/revisions\/163313"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/media\/163312"}],"wp:attachment":[{"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/media?parent=163311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/categories?post=163311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gkseries.com\/blog\/wp-json\/wp\/v2\/tags?post=163311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}