The probability of getting a ‘six’ in the loaded die is 1⁄6 *1.05 = 0.175. The probability of getting a ‘six’ in a normal die is 1⁄6.

P(at least two 6’s in 5 rolls) = 1 - P(zero 6’s in 5 rolls) - P(exactly one 6 in 5 rolls). Then we can find the probability that the die will roll at least 2 ‘six’s in 5 rolls using the following equation: find the probability that the die will roll less than 2 ‘six’s in 5 rolls. The simplest way to solve this question is to find the complementary event of the event described in the question, i.e. The Mathematics section of the CBEST test is comprised of multiple-choice questions only. In work rate problems, unless otherwise stated, you must assume that the rate remains the same whether the two are working together or alone. Therefore, the total amount of days it took Tom and Joan to complete the task: 4 + 6 = 10 days. => 4/5 = (2/15)*y //divide both sides of the equation by (2/15)ĭividing fraction by fraction is the same as multiplying a fraction by the inverse fraction: This means Tom and Joan worked together to complete the remaining 4/5 of the task:Ĥ/5 = ((3 + 5)/60)*y //60 is the common denominator of 20 and 12 => Work = 1/5 => 1/5 of the work was completed by Tom alone. Indicate the number of days Tom and Joan actually worked together as 'y.'īegin with the four days Tom worked on his own due to Joan's leave of absence : To start, use the information obtained from the question: To solve this problem, use the following basic formula: Work = rate*time. Therefore, a 15.66% off coupon for shirts would be necessary in order for Rachel to pay the same amount as if she used the store’s credit card. This price should be the same as the price she would pay using the store’s credit card ($90.44), thus: The price Rachel would have to pay using the coupon is: (1 - C) x 30.40 + 64.80, where C represents the coupon savings. You are asked to find out the percentage coupon for shirts Rachel needs to use in order to pay the same amount as if she received the 5% credit card reduction. If Rachel buys 2 shirts and 3 pants, the price for that purchase is 2 x 15.20 + 3 x 21.60 = 30.40 + 64.80 = $95.20.īy using the store’s credit card and not using any coupons, Rachel receives a 5% discount on the total price which reduces the price to 95.20 x 0.95 = $90.44.

If the pre-sale price of pants was $24 each, then the post-sale price was 24 x 0.9 = $21.60. If the pre-sale price of shirts was $19 each, then the post-sale price was 19 x 0.8 = $15.20.

Cbest math practice test video