← Back to Quizzes Hints: 2/2 Numbers Set -6 Hard Start Your name (optional): Share Certificate Browse Quizzes Play Again [{"type":"single","prompt":"168 \u00f7 4 \u00d7 (9 \u2212 3) + 5\u00b2 = ?","options":["267","271","277","283"],"answer":[2],"explanation":"168 \u00f7 4 = 42; (9\u22123)=6; 42\u00d76=252; 5\u00b2=25; 252+25=277.","hint":"Do bracket \u2192 division \u2192 multiplication \u2192 addition."},{"type":"single","prompt":"40% of a number plus 18 equals 60% of the same number minus 6. What is the number?","options":["80","100","120","140"],"answer":[2],"explanation":"0.40x + 18 = 0.60x \u2212 6 \u2192 18+6 = 0.60x \u2212 0.40x \u2192 24 = 0.20x \u2192 x = 120.","hint":"Take all x-terms on one side, numbers on the other."},{"type":"single","prompt":"Find the next term in the series: 4, 11, 24, 45, 76, ?","options":["111","115","119","123"],"answer":[2],"explanation":"Differences \u2192 11\u22124=7, 24\u221211=13, 45\u221224=21, 76\u221245=31.","hint":"When first differences are not simple, check the differences of differences."},{"type":"single","prompt":"What is the greatest 3-digit number divisible by 12, 15 and 18?","options":["840","900","960","990"],"answer":[1],"explanation":"LCM(12,15,18). 12=2\u00b2\u00d73, 15=3\u00d75, 18=2\u00d73\u00b2 \u2192 LCM = 2\u00b2\u00d73\u00b2\u00d75 = 180.","hint":"First find the LCM, then find its largest 3-digit multiple."},{"type":"single","prompt":"The sum of present ages of A and B is 53 years. One year ago, A was twice as old as B. How old is A now?","options":["33 years","34 years","35 years","36 years"],"answer":[2],"explanation":"Let present ages be A and B.","hint":"Translate both conditions into equations and solve together."},{"type":"single","prompt":"Find the compound interest on \u20b912,500 at 8% per annum for 2 years (compounded yearly).","options":["\u20b91,960","\u20b92,000","\u20b92,080","\u20b92,100"],"answer":[2],"explanation":"Amount = P(1 + r)\u00b2 = 12500(1.08)\u00b2 = 12500\u00d71.1664 = \u20b914,580.","hint":"Use CI formula A = P(1 + r)\u207f, then subtract P."},{"type":"single","prompt":"How many 3-digit even numbers can be formed using the digits 2, 3, 4, 5, 6 without repetition?","options":["24","30","36","42"],"answer":[2],"explanation":"Last digit must be even \u2192 choose from {2,4,6}: 3 ways.","hint":"Fix the last digit (even), then count permutations of the remaining."},{"type":"single","prompt":"A can finish a work in 12 days and B in 18 days. Working together, in how many days will they finish it?","options":["6 days","6.5 days","7.2 days","8 days"],"answer":[2],"explanation":"A\u2019s 1-day work = 1\/12, B\u2019s = 1\/18. Together per day = 1\/12 + 1\/18","hint":"Add their 1-day work, then take the reciprocal."},{"type":"single","prompt":"A sum of money becomes 2.25 times in 10 years at simple interest. What is the rate of interest per annum?","options":["10%","11%","12%","12.5%"],"answer":[3],"explanation":"Amount = P(1 + rt). Given 2.25P = P(1 + r\u00d710).","hint":"\u201cBecomes 2.25 times\u201d means Amount = 2.25\u00d7Principal."},{"type":"single","prompt":"The product of two consecutive integers is 156. What is the smaller integer?","options":["10","11","12","13"],"answer":[2],"explanation":"Let numbers be n and n+1. Then n(n+1) = 156 \u2192 n\u00b2 + n \u2212 156 = 0.","hint":"Consecutive integers \u2192 n and n+1, which gives a quadratic equation."}]
